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"Diatoms—phytoplankton that construct their shells out of silica—are critical to marine food webs and geochemical cycles. They account for ∼40% of marine primary productivity today (1), but are a relatively recent contributor to ocean ecosystems (2). Diatoms first appear in the fossil record in the Jurassic (3) and become ecologically dominant among phytoplankton during the Cenozoic (4, 5). Hypothesized explanations for their middle to late Cenozoic rise include the decline in atmospheric CO2 concentrations over the last 40 My, sea level change, an increase in bioavailable silica reaching the ocean due to elevated continental weathering and/or the expansion of grasslands, and changes in nutrient focusing due to cooler temperatures, among others (5–9)."^[1]

"The timing and cause of diatoms' ascension is important beyond simply reconstructing the history of marine primary producers—it represents a major shift in Earth's silica and carbon cycles. Diatoms are believed to have drawn down ocean silica concentrations to their lowest levels in Earth's history (10), which, studies suggest, could have fundamentally changed climate regulation by altering marine authigenic clay formation (11, 12). A shift from calcifying to silicifying plankton also partially decouples inorganic and organic carbon and leads to a tighter coupling of organic carbon (along with nitrogen and phosphorous) to silica (3, 13, 14). In addition, the evolution of relatively large, well-protected phytoplankton lineages including diatoms, coccolithophores, and dinoflagellates, and their subsequent rise in ecological significance, is hypothesized to be the bottom-up impetus for massive ocean ecosystem restructuring in the Mesozoic and Cenozoic (15)."^[1]

"Recent work (16–18) has called into question the classic timeline of diatoms' increase in abundance and diversity (Fig. 1A). It has been assumed, based on fossil databases, that diatom diversity and abundance were generally very low at the beginning of the Cenozoic and increased toward the present, with a rapid rise beginning around the middle Miocene (23 Ma to 5 Ma) (8, 19, 20). Diatom abundance has, for the most part, been inferred from diatom diversity (21–23), although there is a similar increase in the relative abundance of diatoms in deep-sea sediments (5). Punctuating this long-term trend, siliceous microfossil (and radiolarian) abundance peaks in the Middle Eocene (5, 24) and is followed by a peak in diatom diversity in the latest Eocene to early Oligocene (10, 20, 21, 25, 26). Prior to the ecological rise of diatoms, radiolarians, a group of heterotrophic to mixotrophic protists, were the dominant pelagic silicifiers. As diatoms expanded, seawater silica concentrations are believed to have declined more than tenfold, leading to range contractions, reduced silicification, and reduced abundance in radiolarians and other silicifiers (11, 22, 23, 27–30). However, paired sponge and radiolarian silicon isotope work suggests roughly constant surface water silica concentrations between the latest Paleocene (60 Ma) and the Oligocene (33 Ma), at levels equivalent to modern surface ocean concentrations (<60 µM) (17) (Fig. 1). The Si isotope proxy builds from the observations that the extent of fractionation in sponges is strongly dependent on ambient dissolved Si concentration, while fractionation in radiolarians is mostly Si concentration independent (17, 31–36). In other words, these Si isotope findings suggest that any diatom-driven drawdown of silica must have occurred prior to the late Paleocene. Consistent with this alternative, Si isotope hypothesis, sponge reefs and hypersilicification in neritic sponges (indicative of high silica concentrations) disappeared in the Cretaceous to lower Paleocene (37). However, changes in Si isotope values in the Southern Ocean suggest yet another chronology, with diatom abundance increasing to near modern levels during the Eocene (10)."^[1]

Salt marshes are often overlooked through the lens of groundwater–surface water interactions due to the low permeability of marsh sediments. While a large body of literature exists on groundwater–surface water exchange in the coastal zone [1,2,3], groundwater–surface water exchange in salt marshes is understudied compared to beach and nearshore environments. To this end, tidal marsh hydrogeology has recently been highlighted as a critical knowledge gap in the field [3] and has received renewed attention for its role in mediating chemical exports to the coastal ocean [4,5,6].^[1]

Salt marshes, a subset of coastal wetlands, are fine-grained intertidal ecosystems located along shorelines ranging from ocean margins to the freshwater–seawater interface. Generally, salt marshes consist of a surface unit of organic-rich, low permeability peat, mud, and clay that overtops sandy estuarine sediments, and are therefore distinct from sand-dominated beach environments. The marsh sediment depth varies depending on age, energy regime, and geologic history [7]. These periodically inundated peat- or mud-rich deposits and the area that they encompass are referred to as the marsh platform and are often incised by tidal creeks and channels that act as conduits to the coastal ocean [8]. Salt marshes occur across a range of tidal regimes (i.e., microtidal to megatidal) and geomorphological settings (e.g., restricted-entrance embayment, open coast back-barrier, fringing) [9,10]. Contributing to or stemming from these hydrological and geomorphological characteristics, a diversity of salt- and/or saturation-tolerant plant species colonize marsh platforms including Spartina alterniflora and Spartina patens.^[1]

Rates of groundwater–surface water exchange in salt marshes can greatly exceed inner shelf and beach environments [11], in part due to the unique permeability structure and geometry of marsh ecosystems. Vegetation (rhizomes and roots) [12], bioturbating organisms [13,14], sandy lenses [15] and macropore structures [16] collectively enhance the effective permeability of otherwise muddy, impermeable marsh sediments. Tidal creeks, and thus the creek network type, can enhance the effective area of groundwater–surface water exchange [17]. Marsh sediments and pore waters are frequently enriched in nutrients [18] and carbon [19] relative to coarser-grained systems (i.e., beaches) and have been shown to export vast quantities of carbon and nutrients into tidal creeks and the coastal ocean [20,21].^[1]

The idea that salt marshes export carbon and nutrients to the coastal ocean is the basis of the outwelling hypothesis, which states that salt marshes outwell excess organic matter, dissolved carbon and nutrients to tidal channels, estuaries and the coastal ocean via tidal drainage and exchange [22,23]. Initially, the outwelling discussion was largely centered around nutrient (and predominantly nitrogen) fluxes [20,24,25,26]. Recent advances in blue carbon science have linked salt marshes to regional carbon budgets [5,27,28], thus renewing interest in the outwelling hypothesis. While salt marsh biogeochemistry mediates the quantity and form of nutrients and carbon [29], the magnitude of groundwater–surface water exchange will ultimately drive removal (internal consumption or adsorption onto sediments) or lateral export (i.e., outwelling). Thus, the quantification of salt marsh groundwater–surface water exchange is critical to understand interecosystem variability, and to accurately upscale fluxes between local, regional and global scales.^[1]

Global silicon cycling regulates atmospheric carbon dioxide concentrations via several well-known mechanisms, particularly chemical weathering of mineral silicates [1], occlusion of carbon to soil phytoliths [2], and the oceanic biological silicon pump [3]. The vast majority of research on silicon cycling has focused on the oceans, where silicon-replete diatoms sequester 240 Tmol Si yr⁻¹ [4]. Diatoms are also a critical component of the global carbon cycle, accounting for 35–75% of marine net primary production (NPP) [4] and serving as efficient exporters of carbon to the benthos [5].^[1]

However, similar to diatoms, terrestrial vegetation can also sequester large amounts of silicon. Silicon is considered a "quasi-essential" nutrient for plants [6]. While most plants can grow in silicon-deplete soils, plant fitness is markedly improved with silicon amendments [7]. In fact, silicon is the only element that has been shown to never be toxic to plants even in high doses [7]. Silicon protects plants from a variety of abiotic and biotic stresses, including desiccation, predation, fungal attack, and heavy metal toxicity [6]–[8]. Ultimately, silicon plays a critical role in plant defense [6], which we argue better facilitates plants to perform essential services, particularly carbon sequestration.^[1]

Silicon concentrations in land plants range over two orders of magnitude (<0.1 to over 10% by dry weight (by wt.)), the largest range of any element [6]. All photosynthetic plants contain some silicon within their tissue, often in concentrations equal to or greater than other macronutrients, such as nitrogen (N), phosphorus (P), and potassium (K) [8]. Plants are typically broken into three modes of silicon uptake: rejective, passive accumulators, or active accumulators [7]. Plants whose silicon uptake is greater than that which would passively be taken up through the transpiration stream are defined as active accumulators and typically contain >0.46% silicon (or 1% SiO₂) by weight. [7], [9], [10].^[1]

Plants take up dissolved silica (H₄SiO₄) from soil solution via their roots. Dissolved silica is transported via the xylem for eventual deposition in transpiration termini. Upon incorporation into organisms, biogenic silica is formed, creating siliceous bodies in cell walls known as phytoliths. While the ultimate source of silicon in the biosphere is chemical weathering of mineral silicates, biogenic silica is 7 to 20 times more soluble than mineral silicates [11], resulting in biogenic silica being an important source of dissolved silica on biological time scales [12]. The dynamic cycling of silicon on its path from land to sea has only recently been documented [11], [13], demonstrating that the biological component of the global silicon cycle is driven not only by diatoms, but also by terrestrial organisms [14].^[1]

Because certain plants, such as grasses, fix more Si than others, fixation of Si on land is far from uniform.^[1]

ABSTRACT: Silicon (Si) cycling controls atmospheric CO2 concentrations and thus, the global climate, through three well-recognized means: chemical weathering of mineral silicates, occlusion of carbon (C) to soil phytoliths, and the oceanic biological Si pump. In the latter, oceanic diatoms directly sequester 25.8 Gton C yr−1, accounting for 43% of the total oceanic net primary production (NPP). However, another important link between C and Si cycling remains largely ignored, specifically the role of Si in terrestrial NPP. Here we show that 55% of terrestrial NPP (33 Gton C yr−1) is due to active Si-accumulating vegetation, on par with the amount of C sequestered annually via marine diatoms. Our results suggest that similar to oceanic diatoms, the biological Si cycle of land plants also controls atmospheric CO2 levels. In addition, we provide the first estimates of Si fixed in terrestrial vegetation by major global biome type, highlighting the ecosystems of most dynamic Si fixation. Projected global land use change will convert forests to agricultural lands, increasing the fixation of Si by land plants, and the magnitude of the terrestrial Si pump.^[1]

Silicon (Si) is the second most abundant element in the Earth’s crust, and is released as silicic acid [dissolved silica (DSi); Si(OH)4] via weathering. A variety of marine organisms are silicifiers including diatoms, radiolarians, silicoflagellates, select sponges, and even picocyanobacteria (Tréguer and De La Rocha, 2013). Photosynthesizing silicifiers (e.g., diatoms) take up significant amounts of Si along with nitrogen, phosphorus, and inorganic carbon, tightly coupling these biogeochemical cycles (Tréguer et al., 2021). Diatoms are responsible for ∼50% of oceanic primary productivity (Rousseaux and Gregg, 2013) and are an important source of carbon (C) export to the deep ocean (Tréguer et al., 2018). Diatoms also play a key role in coastal productivity and food web structure (Hackney et al., 2002).^[1]

Over 80% of the annual inputs of DSi to the global ocean comes from land (Tréguer and De La Rocha, 2013). While rivers are the primary transport mechanism, the path of DSi from land to sea is not direct (Struyf and Conley, 2012). Over the last two decades a new paradigm has emerged that highlights the importance of Si uptake by terrestrial vegetation, with land plants intercepting Si as it makes its way along the land-ocean continuum (Conley, 2002; Carey and Fulweiler, 2012). In fact, Si is rapidly recycled through the terrestrial plant reservoir, and this terrestrial cycle helps regulate the flux of Si from continents (Conley, 2002; Carey and Fulweiler, 2012; Struyf and Conley, 2012). Plants take up DSi from the soil solution and groundwater via their roots and transport it throughout the plant where it is deposited as biogenic silica (BSi; Epstein, 1994; Raven, 2003). BSi mostly accumulates as siliceous bodies known as phytoliths at transpiration termini (Epstein, 1994; Raven, 2003). Plants return this BSi to soils, chiefly as litter fall, where it dissolves seven to 20 times faster than mineral silicates (Fraysse et al., 2009; Cornelis et al., 2011). Thus on biological time scales, terrestrial vegetation plays an important yet not fully understood role in altering Si cycling within and across ecosystems.^[1]

Wetlands are borderland ecosystems–not quite terrestrial, not quite aquatic. Yet, they play an important role in regulating the availability of Si in downstream ecosystems. All plants contain some Si in their tissue, with concentrations ranging from <0.1 to 10% by dry weight (Epstein, 1999; Raven, 2003; Hodson et al., 2005). Some plants, like those that characterize wetlands (e.g., grasses and sedges), have particularly high BSi concentrations. Thus wetlands are described as “hot spots” for Si cycling (Struyf and Conley, 2009). Wetland sediments also typically contain elevated amorphous silica (ASi) concentrations (Norris and Hackney, 1999; Struyf et al., 2010), particularly in the top sediment layers (Carey and Fulweiler, 2013). ASi is comprised mostly of the BSi fraction in soils, sourced from both plant BSi and benthic algae growth (Carey and Fulweiler, 2013). ASi is also comprised of the non-mineral pedogenic fraction, such as the Si sorbed to iron and aluminum oxi/hydroxides (Saccone et al., 2007; Cornelis et al., 2011). Substantial research effort has focused on Si cycling in temperate wetland ecosystems, specifically tidal freshwater and saltwater marshes, where large Si reservoirs in sediments, plants, and porewater have been documented (Struyf et al., 2005; Carey and Fulweiler, 2013; Müller, 2013). Tidal exchange connects salt marsh Si reservoirs to adjacent estuarine systems, often supplying substantial quantities of DSi to marine waters (Vieillard et al., 2011; Müller et al., 2013; Carey and Fulweiler, 2014a).^[1]

While evidence points to the dynamic and critical role of salt marshes in coastal temperate Si cycling, the role of salt marshes’ lower latitude counterpart–mangroves–in tropical coastal Si cycling remains unknown. We hypothesized that mangroves are significant reservoirs of Si and that their high productivity could make them an important, yet overlooked, driver of tropical Si cycling.^[1]

Bernard Richards studied mathematics and physics for his bachelor's degree.^[1] For his master's degree, he worked under the supervision of Alan Turing (1912–1954) at Manchester as one of Turing's last students, helping to validate Turing’s theory of morphogenesis.^[2][3][4]

"Turing was keen to take forward the work that D’Arcy Thompson had published in On Growth and Form in 1917".^[4]

• Spine variations in radiolarians as discovered by HMS Challenger in the 19th century and drawn by Ernst Haeckel

• Cromyatractus tetracelyphus with 2 spines

• Circopus sexfurcus with 6 spines

• Circopurus octahedrus with 6 spines and 8 faces

• Circogonia icosahedra with 12 spines and 20 faces

• Circorrhegma dodecahedra with 20 (incompletely drawn) spines and 12 faces

• Cannocapsa stethoscopium with 20 spines

The gallery shows images of the radioarians as extracted from drawings made by the German zoologist and polymath Ernst Haeckel in 1887.

As primary producers, phytoplankton form the base of the pelagic environment of freshwater ecosystems. A healthy, diverse phytoplankton community is necessary for proper ecosystem function and balance, playing a substantial role in important ecosystem processes, such as nutrient and organic matter cycling. Diversity is maintained through species interactions (e.g., competition for resources, epiphytic associations, antagonistic behavior), shifting environmental conditions, and periodic disturbances (Biddanda et al., 2021, Sigee, 2005). In temperate dimictic freshwater lakes, such as those in the Great Lakes region, a predictable seasonal succession of phytoplankton community composition responds to temporal shifts in environmental variables. Briefly, phytoplankton growth is comparatively low in the winter; a diatom bloom occurs in the spring, as diatoms thrive in turbulent, low-light environments and variable nutrient concentrations; in late-spring, a clear-water phase occurs as resources deplete and zooplankton grow; small, fast-growing, inedible species (e.g., cryptomonads and chlorophytes) occur in low abundance near the end of this phase; a mixed bloom occurs in the summer and fall, including cyanobacteria, cryptophytes, chlorophytes, and dinoflagellates; and then diatoms often see a fall resurgence (Dodds and Whiles, 2019, Sommer, 1989).^[1]

While phytoplankton are cosmopolitan in nature, their diversity is found to vary across latitudinal, longitudinal, and altitudinal gradients (Stomp et al., 2011). Phytoplankton community diversity is largely controlled through bottom-up mechanisms, such as nutrients, temperature, and light. Therefore, changes in land use and climate that impact local environmental variables threaten the biological integrity of the phytoplankton community (Stomp et al., 2011, Zhang et al., 2016). Furthermore, Ptacnik et al., 2008, Ye et al., 2019 found that resource use efficiency positively correlated with phytoplankton diversity in freshwater, marine, and brackish ecosystems. Therefore, anthropogenically induced changes in community composition can lead to community imbalances, decreased diversity, reduced carbon cycling efficiency, and inability of phytoplankton to maintain stable populations (Bergkemper et al., 2018, Ptacnik et al., 2008, Urrutia-Cordero et al., 2017, Ye et al., 2019). As low points in the landscape that integrate changes in the watershed, lakes serve as reliable sentinels of climate change and hot spots of carbon cycling (Biddanda, 2017, Williamson et al., 2009). As such, phytoplankton are useful indicators of changing conditions due to their fast growth rates, short life cycles, high abundance, small size, and high reactivity (Cai and Reavie, 2018, Reavie et al., 2014b).^[1]

Cyanobacteria are ubiquitous, finding habitats in most water bodies and in extreme environments such as the polar regions, deserts, brine lakes and hot springs.^[1][2][3] They have also evolved surprisingly complex collective behaviours that lie at the boundary between single-celled and multicellular life. For example, filamentous cyanobacteria live in long chains of cells (figure 1) that bundle together into larger structures including biofilms, biomats and stromatolites.^[4][5] These large colonies provide a rigid, stable and long-term environment for their communities of bacteria. In addition, cyanobacteria-based biofilms can be used as bioreactors to produce a wide range of chemicals, including biofuels like biodiesel and ethanol.^[6] However, despite their importance to the history of life on Earth, and their commercial and environmental potentials, there remain basic questions of how filamentous cyanobacteria move, respond to their environment and self-organize into collective patterns and structures.^[7]

All known cyanobacteria lack flagella;^[8] however, many filamentous species move on surfaces by gliding, a form of locomotion where no physical appendages are seen to aid movement.^[9] The actual mechanism behind gliding is not fully understood, although over a century has elapsed since its discovery.^[10][11] One theory suggests that gliding motion in cyanobacteria is mediated by the continuous secretion of polysaccharides through pores on individual cells.^[12][13][14] Another theory suggests that gliding motion involves the use of type IV pili, polymeric assemblies of the protein pilin,^[15] as the driving engines of motion.^[16][17][18] However, it is not clear how the action of these pili would lead to motion, with some suggesting they retract,^[19], while others suggest they push,^[20] to generate forces. Other scholars have suggested surface waves generated by the contraction of a fibril layer as the mechanism behind gliding motion in Oscillatoria.^[21][22] Recent work also suggests that shape fluctuations and capillary forces could be involved in gliding motion.^[23][7]

Through collective interaction, filamentous cyanobacteria self-organize into colonies or biofilms, symbiotic communities found in a wide variety of ecological niches. Their larger-scale collective structures are characterized by diverse shapes including bundles, vortices and reticulate patterns.^[24][25] Similar patterns have been observed in fossil records.^[26][27][28] For filamentous cyanobacteria, the mechanics of the filaments is known to contribute to self-organization, for example in determining how one filament will bend when in contact with other filaments or obstacles.^[29] Further, biofilms and biomats show some remarkably conserved macro-mechanical properties, typically behaving as viscoelastic materials with a relaxation time of about 20 min.^[30][7]

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Header text	google	scholar	books
recalcitrant doc	5,340	659	448
refractory doc	8,510	1270	937
semi-refractory
labile doc	21,500	3130	1260
semi-labile

"Labile" recalcitrant|refractory "dissolved organic carbon"|"dissolved organic matter"|"dissolved organic material" labile

humic non-humic purgeable particulate

"particulate organic carbon" "purgeable organic carbon"

"organic carbon"|"organic matter" recalcitrant|refractory humic purgeable ^[1]

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ORIGIN & FATE OF MARINE ORGANIC CARBON - Organic matter from phytoplankton cells utilized (by bacteria), grazed (by zooplankton) & lysed (by viruses) UNPUBLISHED: Klip, H.C.L. (2019) Faculty of Geosciences Theses (Master thesis) Abstract "In the marine realm, phytoplankton form the base of the food web and are key for the biological pump. While bottom-up factors regulate phytoplankton productivity and growth, top-down factors (e.g. predation, viral lysis, and sedimentation) regulate their standing stock. Due to viral lysis, particulate organic matter (POM) is transferred to dissolved organic carbon. Thereby, organic matter and energy are shunted towards the microbial loop and away from higher trophic levels. The aim of this MSc project is to investigate different pathways of organic matter and aggregate production, i.e. through viral lysis (from POM to DOM) of 2 phytoplankton species, and sloppy feeding and egestion by 2 zooplankton species. Fluorescent dissolved organic matter (FDOM) production was followed over time using axenic and non-axenic cultures to which bacteria were added in order to study the influence of bacterial presence on the FDOM composition. Additionally, the potential effects of cell size and temperature were taken into account. The results from the zooplankton experiments focusing on sloppy feeding showed that the FDOM quality is taxonomic phylum specific with the ciliate producing relatively more labile and the heterotrophic nanoflagellate more refractory FDOM, which is likely due to different feeding strategies. For the viral lysis derived FDOM, the results showed increased labile FDOM production under axenic conditions with a distinct impact on the share of labile and refractory by bacterial presence. Results varied with phytoplankton species (Phaeocystis globosa produced more FDOM compared to Micromonas commoda). Overall, the results indicate that nano- and microzooplankton as well as viral lysis and bacterial presence display a strong control on FDOM quantity and quality, which is of imperative importance for organic carbon cycling."

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Inorganic carbon is carbon extracted from ores and minerals, as opposed to organic carbon found in nature through plants and living things. Some examples of inorganic carbon are carbon oxides such as carbon monoxide and carbon dioxide; polyatomic ions, cyanide, cyanate, thiocyanate, carbonate and carbide in carbon

"POC can be a good indicator of productivity in the euphotic zone. In terms of sea ports, the biotic and detritus components of POC could be used as indicators of pollution."

Laminarin is a major molecule in the marine carbon cycle.^[3] Microscopic planktonic algae are the base of the marine food web. Although sugars are the most abundant biomolecules in land plants, their concentrations in marine plants appear surprisingly low. In 2020, Becker et al. used recently discovered enzymes to dissect microalgae inhabiting the sunlit ocean and found that 26 ± 17% of their biomass consists of the sugar polymer laminarin.^[3] The concentration in algal cells increased markedly during the day, in analogy to the seasonal storage of energy in starchy roots and fruits of land plants. Vast quantities of laminarin discovered in the ocean underscore the importance of marine sugars in the global carbon cycle.^[3]

Marine microalgae sequester as much CO₂ into carbohydrates as terrestrial plants. Polymeric carbohydrates (i.e., glycans) provide carbon for heterotrophic organisms and constitute a carbon sink in the global oceans. The quantitative contributions of different algal glycans to cycling and sequestration of carbon remain unknown, partly because of the analytical challenge of quantifying glycans in complex biological settings. Becker et al. measured laminarin along transects in the Arctic, Atlantic, and Pacific oceans and during three time series in the North Sea. These data revealed a median of 26 ± 17% laminarin within the particulate organic carbon pool. The observed correlation between chlorophyll and laminarin suggests an annual production of algal laminarin of 12 ± 8 gigatons: that is, approximately three times the annual atmospheric carbon dioxide increase by fossil fuel burning. Their data also suggests that laminarin accounts for up to 50% of organic carbon in sinking diatom-containing particles, thus substantially contributing to carbon export from surface waters. Laminarin concentrations in the sunlit ocean are driven by light availability. Collectively, these observations highlight the prominent ecological role and biogeochemical function of laminarin in oceanic carbon export and energy flow to higher trophic levels.^[3]

The production rate of organic carbon is controlled by the growth of photosynthetic microalgae in the sunlit ocean, where diatoms alone contribute about 40% of the marine primary production and convert equal amounts of carbon dioxide into biomass as tropical forests.^[2][3]

Prokaryotic life has dominated most of the evolutionary history of our planet, evolving to occupy virtually all available environmental niches. Extremophiles, especially those thriving under multiple extremes, represent a key area of research for multiple disciplines, spanning from the study of adaptations to harsh conditions, to the biogeochemical cycling of elements. Extremophile research also has implications for origin of life studies and the search for life on other planetary and celestial bodies.^[1]

Over the past century, the boundary conditions under which life can thrive have been pushed in every possible direction, encompassing broader swaths of temperature, pH, pressure, radiation, salinity, energy, and nutrient limitation. Microorganisms do not only thrive under such a broad spectrum of parameters on Earth, but can also survive the harsh conditions of space, an environment with extreme radiation, vacuum pressure, extremely variable temperature, and microgravity (Horneck et al., 2010; Yamagishi et al., 2018). The definition of “extreme conditions” has strong anthropocentric criteria, rather than microbial criteria, and can be the cause of confusion (Rothschild and Mancinelli, 2001). When considering extremophilic (as opposed to extremotolerant) organisms, it is important to keep in mind that these are highly adapted organisms for the conditions considered and that the “extreme” condition constitutes the norm under which the organism is able to metabolically and biochemically operate. Moreover, there are myriad environments on our planet’s surface – and especially subsurface – that exhibit extremes in one or more physical or chemical condition. Therefore, extremophiles and, in particular, polyextremophiles (Capece et al., 2013) might be the most abundant lifeforms on our planet. In addition, if we consider that the current planetary surface conditions on Earth (such as mean temperature, redox state, and oxygenic atmosphere) have only occurred for a short period of time compared to the existence of life (Knoll, 2015), we might conclude that the extremophilic way of life has actually dominated the evolutionary history of life on our planet.^[1]

Over the past several decades, the isolation of culturable (poly)extremophiles and the identification of extreme microbial communities through various culture-independent approaches have provided key insights into the boundaries of life. Research on (poly)extremophiles has led to numerous advances in molecular biology and medicine (Babu et al., 2015; Coker, 2016; Durvasula and Rao, 2018), while simultaneously reshaping our understanding of the origins and evolution of life (Bertrand et al., 2015) and the potential for life on other planetary bodies (Schulze-Makuch, 2013). Several reviews have defined extremophiles (Table 1) (e.g., Rothschild and Mancinelli, 2001; Fang et al., 2010; Capece et al., 2013; Seckbach et al., 2013) and discussed the physiology and genetics of (poly)extremophiles in detail (e.g., chapters within Polyextremophiles: Life Under Multiple Forms of Stress, edited by Seckbach et al., 2013).^[1]

Our knowledge of life is based on the observable and measurable phenomena that occur on Earth, and is therefore limited to this instance of life. However, the laws of chemistry and physics have universal principles which enable us to extrapolate to the conditions under which life could survive elsewhere. These principles suggest that life requires a liquid solvent, an energy source, and building blocks (Schwieterman et al., 2018).^[1]

While the bulk abundance of (inorganic) building blocks appears not to be a factor limiting the distribution of life on Earth (with subsurface environments as a possible exception, e.g., Hoehler and Jørgensen, 2013) and, potentially, other planetary bodies, the availability of a solvent is considered to be a key factor. While the potential for other liquid solvents to sustain extraterrestrial life is discussed in detail elsewhere (Schwieterman et al., 2018 and references therein), water is considered the most likely liquid solvent because of its cosmic abundance and physicochemical properties (Michiels et al., 2008; Schwieterman et al., 2018). Water, especially the availability of liquid water, appears to be the main factor controlling the dimensions of the biospace for life on Earth (i.e., the parameter space occupied by life). Liquid water acts both as a solvent and a reactant/product in biochemical reactions, and its numerous unique physicochemical properties have profoundly shaped the emergence and evolution of life on our planet. As discussed in this review below, water activity appears to be the single key parameter controlling the biospace of Earth’s life, and numerous other parameters limiting life (e.g., temperature and salinity) are, in fact, acting on the availability of water. At the ecosystem level, water can indirectly influence the variation of key physicochemical conditions, which in turn controls microbial community composition and diversity, profoundly influencing geobiochemical cycling (sensu Shock and Boyd, 2015).^[1]

Life also needs a source of energy to power chemical reactions, and redox chemistry appears to be universal (Jelen et al., 2016). Physicochemical gradients create non-equilibrium redox conditions that have played an important role in the origins, evolution, and diversity of life. Redox and proton gradients were likely the two main mechanisms involved in the origins of life, initiating the necessary energy flux to drive metabolism and growth (Lane et al., 2010; Lane and Martin, 2012). Therefore, the current search for life’s limits has extended beyond temperature, pH, pressure, salinity, and radiation gradients (each parameter discussed in their respective sections) and also includes the possible energetic and nutrient limits of life (discussed in Hoehler and Jørgensen, 2013; LaRowe and Amend, 2015; Jones et al., 2018).^[1]

The parameters discussed herein (temperature, pH, pressure, salinity, and radiation) correlate with each other and can influence the availability of nutrients and energy sources. Depending on the environment, certain parameters can more strongly influence microbial diversity over others, such as temperature in geothermal waters (Sharp et al., 2014), pH in soil communities (Rousk et al., 2010), salinity in saline lakes (Yang et al., 2016), and water content in dry climates (Dose et al., 2001). On the nano- and micro-scale level, the two most important factors are likely water activity and pH, which influence the chemiosmotic, energy-generating gradient at the cell level (Lane et al., 2010; Lane and Martin, 2012). In contrast, parameters that influence the macro-scale level vary with the ecosystem. For example, temperature plays a significant role in geothermal environments and influences such processes as water-rock interactions and degassing (Nordstrom et al., 2005; Fouke, 2011; Cole et al., 2013; Price and Giovannelli, 2017). Water-rock interactions can then impact microorganisms by limiting the availability of trace elements and electron donors/acceptors.^[1]

Microorganisms have been detected in a variety of extreme environments (Figure 1), virtually in any location where liquid water is available for life to use. This demonstrates that life can adapt to a wide range of parameters (Figure 2). It is therefore imperative to determine the minima and maxima for each parameter, and even more importantly, to understand their combined effects, in order to evaluate the limits of Earth’s life and advance our understanding of the potential for life elsewhere.^[1]

Extremely low and high pH environments have been observed for different ecosystems on Earth (Table 2). Extreme pH values were observed for ecosystems contaminated by mining waste, with current extremes reported from Iron Mountain (Shasta County, CA, United States) (pH -3.6) (Nordstrom et al., 2000) and Gorka Lake (Chrzanow region, Poland) (pH 13.3; Czop et al., 2011). While there has yet to be any microbial community studies or isolation attempts for Gorka Lake, to the best of our knowledge, microbial communities have been explored at Iron Mountain (Baker and Banfield, 2003), with several microorganisms isolated [e.g., Thermoplasmales (Edwards et al., 2000), Acidithiobacillus ferrooxidans (Schrenk et al., 1998; Kelly and Wood, 2000), and Leptospirillum ferrooxidans (Schrenk et al., 1998)]. Despite this, there are currently no cultured or isolated microorganisms which can be grown at either of the listed extremes. Currently, the most extreme acidophile and alkaliphile can survive at pH 0 and pH 12.5, respectively (pHopt 0.7 and 11) (Table 3). The lowest pHmin -0.06 was observed for two hyperacidophilic Archaea known as Picrophilus oshimae and P. torridus (pHopt 0.7), isolated from a solfataric hot spring in Noboribetsu (Hokkaido, Japan) (Schleper et al., 1996). These heterotrophic and aerobic polyextremophiles can also withstand temperatures of up to 65°C (Topt = 60°C, Tmin = 47°C), potentially through increased cyclization of their tetraether membrane lipids as a generalized response to pH, temperature, and nutrient stress (Feyhl-Buska et al., 2016). Other thermoacidophiles also include those species within the genus Sulfolobus, in which several isolates are known to be genetically tractable (Quehenberger et al., 2017). In comparison to extreme acidophily, the highest pHmax of 12.5 was observed for an alkaliphilic, aerobic, mesophilic bacterium known as Serpentinomonas sp. B1 (pHopt 11), isolated from a terrestrial serpentinizing system, The Cedars (CA, United States) (Suzuki et al., 2014). Although there is a report of the highest pHmax 13 held by Plectonema nostocorum (Kingsbury, 1954), this has not been further confirmed. The largest pH range, as compared to other isolated microorganisms, was observed for Halomonas campisalis (pHrange 6–12), a haloalkaliphilic bacterium isolated from a soda lake (Soap Lake, WA, United States) (Mormile et al., 1999; Aston and Peyton, 2007) (Table 4).^[1]

The pH has a significant effect on microorganisms and microbial consortia, ranging from the nano- to macro-scale level. All microorganisms must maintain a near neutral cytoplasmic pH to enable cellular functions for survival and metabolism (Krulwich et al., 2011; Jin and Kirk, 2018). The cytoplasmic pH of acidophilic bacteria is ∼6.0 while alkaliphilic bacteria have a cytoplasmic pH around 7.2–8.7 (Krulwich et al., 2011). For more information on the molecular mechanisms behind pH homeostasis, Krulwich et al. (2011) provide a detailed review. The homeostasis of protons (and other ions) through various transporters, including the ion-utilizing ATP synthase, was likely one of the first functions to develop within the earliest cells (Lane and Martin, 2012). Indeed, chemiosmosis is a property of both archaeal and bacterial cells (Lane et al., 2010). In addition to intracellular pH, microorganisms can excrete organic metabolites, such as lactic acid or acetic acid, thereby changing the immediate, surrounding pH (Zhang et al., 2016). Many acidophiles also have organic acid degradation pathways to prevent proton uncoupling by organic acids (Baker-Austin and Dopson, 2007). It has been demonstrated both in natural settings and laboratory cultures that microorganisms can significantly alter their environmental pH as a result of metabolic reactions. For example, sulfide, thiosulfate, and elemental sulfur oxidizers secrete sulfate and protons as by-products, significantly acidifying their environment. This ability is used industrially for the bio-leaching of sulfide ore deposit (Olson et al., 2003; Rohwerder et al., 2003) and it is largely responsible for the low pH of acid mine drainage fluids and other acidic environments. Recent work by Colman et al. (2018) suggests that thermoacidophilic archaea and the acidity of their habitats co-evolved after the evolution of oxygenic photosynthesis (since oxygen is used as primary electron acceptor in the metabolisms), showing a significant example of niche engineering and geosphere-biosphere coevolution. All together, these findings suggest that pH can be metabolically controlled either at the intracellular or local level, as compared to temperature, radiation, salinity, and pressure.^[1]

On the macro-scale level, pH can dominate as the main parameter affecting microbial community composition and abundances. Several studies demonstrate that pH affects microbial community diversity more than any other parameter tested (e.g., Lauber et al., 2009; Rousk et al., 2010; Xiong et al., 2012; Kuang et al., 2013; Zhalnina et al., 2014). For example, distinct microbial communities were observed with changes in pH (pHrange 1.9–4.1), in which the genus Ferrovum dominated at higher pH while the phyla Alphaproteobacteria, Gammaproteobacteria, Nitrospirae, and Euryarchaeota were present at lower pHs (Kuang et al., 2013). Similarly, bacterial community composition changed with increasing pH in alkaline sediments of a Tibetan plateau (pHrange 6.88–10.37) (Xiong et al., 2012). Changes in community composition are likely derived from the range in which microorganisms can survive (Fernández-Calviño and Bååth, 2010). Most cultured microbes live within a narrow pH range of three to four units (Rosso et al., 1995), although some exceptions occur [e.g., fungal isolates can grow over five to nine pH units (Wheeler et al., 1991; Nevarez et al., 2009)]. Moreover, it has been suggested that archaeal (Kuang et al., 2013) and fungal communities (Rousk et al., 2010) may be less affected by changes in pH compared to bacteria.^[1]

Biofilms, biocrusts and cyanobacteria

Biocrusts are important functional units in dryland ecosystems. Regarded as ecosystem engineers, cyanobacteria in biocrusts contribute several major physico-chemical and biological processes. However, the role of cyanobacteria in the process of loess formation has been underestimated. The role of cyanobacteria in loess formation has only recently been recognized and the possible biogenic nature of loessification is underestimated as compared to their eolian nature. Mineral weathering and mineral precipitation processes as well as mineral dust flux between litho- and atmosphere mediated by cyanobacteria and biocrusts require more attention due to their significant contribution to ecosystem properties.^[1]

The role of cyanobacteria in loess formation has only recently been recognized and the possible biogenic nature of loessification is underestimated as compared to their eolian nature. Mineral weathering and mineral precipitation processes as well as mineral dust flux between litho- and atmosphere mediated by cyanobacteria and biocrusts require more attention due to their significant contribution to ecosystem properties.^[1]

Throughout the world, drylands are the most often encountered biotopes of biocrusts (Makhalayane et al. 2015; West 1990), where they can cover up to 70% of the surface (Buis et al. 2009; Karnieli et al. 2002). Biocrusts are present on all seven continents and in all climatic regions (Belnap and Lange 2003). They are particularly significant in the ecology of arid and semi-arid regions (Belnap 2006; Chamizo et al. 2012; Kidron et al. 2010). Biocrusts represent associations of sediment/soil particles with bacteria, cyanobacteria, algae, fungi, lichens and mosses (Belnap and Lange 2003; Chamizo et al. 2012; Evans and Johansen 1999; Hu et al. 2002a) and their secreted metabolites (primarily exopolysaccharides) (Lan et al. 2012), as well as microfauna (Pócs et al. 2006). As a highly productive microenvironment, biocrusts establish and control basic physico-chemical processes of the ground surface, influencing environmental properties at micro and macro scales. Biocrusts also influence soil development, hydrological processes, water and energy balance, nutrient content, soil temperature, movement of gases, eolian particle (dust) uptake and deposition and eventually, plant community development (Weber et al. 2016).^[1]

Biocrust diversity is characterized by spatial and temporal variability (Williams et al. 2013), resulting in a succession of autochthonous life forms, with cyanobacteria being common components (Belnap 2001; Lan et al. 2013). The abundance of cyanobacteria in biocrusts of arid and semi-arid regions distributed around the world is significant (Colesie et al. 2016, Fig. 9.4). The cyanobacteria observed in biocrusts belong to at least 48 genera, of which 8 genera are present in all investigated regions (Colorado, Southeastern Utah, Northwestern Ohio, Mexico, India, Southern Africa, Israel, Iran and Spain).^[1]

Xerotolerance is one of the major ecophysiological adaptations shaping microbial communities in arid and semi-arid conditions. Cyanobacteria tend to dominate microbial populations in desert biocrusts (Makhalayane et al. 2015; Potts 1994), reflecting their successful survival strategies against desiccation, the ability to cope with transient changes between hot/dry and warm/humid conditions, and versus exposure to high irradiance by visible and UV light (Whitelam and Codd 1986). Cyanobacteria can function as primary colonizers via their ability to grow photoautotrophically and the capacity of some members to fix atmospheric nitrogen. Surface colonization can be further enabled by the production of exopolymeric substances (EPS) leading to biofilm formation or to complex, multilayered microbial mats. Cyanobacterial EPS contains sulphate groups and uronic acids, which give the EPS an anionic and sticky character (Rossi and De Philippis 2015). The EPS layer also minimizes water loss and reduces UV irradiation reaching the cells, thus protecting against abiotic stress factors. Microalgae and mosses are generally unable to function as primary colonizers of constrained environments themselves, and depend on cyanobacteria to provide stable hydrated microenvironments with necessary nutrients (Zhang et al. 2015). In addition, cyanobacteria possess extensive metabolic responses that help them to cope with fluctuations in moisture and irradiance, and to pass through active-dormant-active transitions. Efficient protection of macromolecules constitutes one survival strategy of extremophilic and extremotolerant cyanobacteria. Protein denaturation in water-deficient cells is prevented by the accumulation of osmolytes including, intracellular sucrose and trehalose in drought-resistant cyanobacteria (Hershkovitz et al. 1991). Further defense mechanisms are used against reactive oxygen species (ROS) which cause damage to membranes, nucleic acids and proteins (Whitelem and Codd 1986; Billi and Potts 2002). ROS generation is accelerated under typical dehydrating conditions, i.e. strong sunlight/UV irradiation. Damage by ROS is partly controlled by cyanobacterial Fe-superoxide dismutase that neutralizes formed superoxide radicals (Shirkey et al. 2000). To prevent ROS generation by UV, cyanobacteria synthesize UV-absorbing scytonemin (Garcia-Pichel and Castenholz 1991) and mycosporine-like amino acids (MAAs) (Cockell and Knowland 1999; Garcia-Pichel and Castenholz 1993; Rastogi et al. 2014).^[1]

The role of biocrust cyanobacteria in sediment particle accumulation and preservation of land surfaces has long been recognized (Belnap and Gardner 1993). The BLOCDUST hypothesis (Biological LOess Crust – DUSt Trapping) (Svirčev et al. 2013) postulates the role of cyanobacterial biocrusts in the process of loess formation. According to this hypothesis, the accumulation/growth of loess sediment in arid and semi-arid regions is supported via the trapping and accumulation of airborne dust particles during wet events by sticky cyanobacterial EPS. Intervening dry periods provide conditions for the preservation of particles captured and covered by firm biocrusts.^[1]

Loess and related deposits are one of the most widespread Quaternary aeolian sedimentary formations, most abundant in semi-arid regions of inner Eurasia (Muhs 2013; Smalley et al. 2011). They present and preserve parent material for the synsedimentary formation of soils, such as fertile chernozem. Moreover, loess has a more applied role and presents a widespread building ground with specific geotechnical properties (Sprafke and Obreht 2016). Despite its importance, the processes required for loess formation are still not fully understood (Sprafke and Obreht 2016). Loess is usually defined as eolian sediments formed by the accumulation of wind-blown dust particles. However, this definition does not cover post-depositional processes related to the formation of loess structure. Typically, loess sediments have homogenous and highly porous structures, with particles loosely cemented by microcrystalline calcium carbonate derived from corrosion and re-precipitation of detrital carbonates (Muhs 2007; Muhs and Bettis 2003; Pésci 1990; Smalley et al. 2006). The formation of a typical loess structure is usually attributed to a process called loessification. Unfortunately, this process is still poorly understood because it is related to processes similar to pedogenesis (neo-formation of clays and Fe-oxides, and carbonate re-precipitation) and diagenesis (cementation of the particles and stabilization of sediment structure), placing loessification in between those processes (Pécsi 1990, 1995; Sprafke and Obreht 2016). In addition, the mechanisms of particle entrapment during dust accumulation are not fully understood. The role of cyanobacteria within biocrusts and processes related to their activity, however, have the potential to explain the processes of particle entrapment, accumulation and preservation. Here, we propose processes facilitated by cyanobacteria and their relation to loess formation. Besides construing the bio-geological importance of cyanobacteria and biocrusts, this article proposes distinct definitions of some ambiguous key terms and introduces a new term: “synergosis”. Further, the possible health significance of dust particle accumulation and of toxins potentially produced by biocrust cyanobacteria is also discussed.^[1]

There is a lack of clear definitions in the terminology of biological crusts. According to some definitions, biocrusts are characterized by periodical or permanent surface features influenced by factors including soil structure and type, irradiance, topographic attributes (Belnap 1995; Hu and Liu 2003; Lange et al. 1997; Zaady et al. 2000), mineral resources and water (Pickett and McDonnell 1989). We refer to a biocrust as a hardened, crisp structure formed by drying, consisting of living but dormant, highly specialized organisms in close association with sediment/soil particles. In describing the changes in biocrust physical properties, some language problems can lead to the use of terms that are redundant (pleonasms) or even contradictory. It can be easily observed that environmental changes between dry and wet events readily lead to a shift between the desiccated and hydrated appearance of biocrusts. In this context “dry biocrust”, the term commonly used in the literature, is pleonastic and “wet biocrust” is contradictory.^[1]

When a biocrust becomes hydrated and active due to wetting, it can act as a biological terrestrial mat, a fully functional biological community. The early-developmental stages of hydrated biocrusts (Zhang 2005) improve the surface microenvironment, which in turn provides further aid to colonization and supports the survival of later successional stages (Acea et al. 2003; Hu and Liu 2003; Kurina and Vitousek 1999; Langhans et al. 2010; Lukešová 2001). By synthesizing significant amounts of EPSs, cyanobacteria can promote further growth of the microcommunity and may enable protozoa, small invertebrates and microfungi to become established. Biological terrestrial mat development continues until a climax community is established under given environmental conditions. Further successional steps may lead to the formation of vegetation (if the wet period continues) or the community may reverse to the crust stage (if dry conditions return).^[1]

So far, biocrusts have been referred to by multiple names (cryptogamic, microbiotic, cryptobiotic and microphytic crusts) indicating some common features of the constituent organisms, but the most often-used term is “biological soil crust” (BSC) (Belnap et al. 2003a; Langhans et al. 2009). Many factors can be used to classify BSCs (Belnap 2003a; Berkeley et al. 2005; Dougill and Thomas 2004; Langhans et al. 2009; Pócs 2009) but especially important are the physicochemical properties of the growth surface (Chamizo et al. 2012). Regarding this factor, the question arises as to whether the term biological soil crusts can be used for all biocrusts. Declaring all biocrusts as soil crusts can lead to misunderstandings in both a scientific and etiological sense. Crust types differ from physical crusts to biocrusts, where different biological crust types can be described and called by specific names: biocrusts formed on soil, loess, sand, rocks and other substrates, differing in physical and chemical properties.^[1]

While substrates, such as unconsolidated sediments (e.g. sand), and sedimentary, metamorphic or magmatic rocks are provided with a clear definition of their structure and genesis, this is not the case with the loess substrate. The specificity of loess lies in its polygenetic nature (Sprafke and Obreht 2016), determined by complex environmental sedimentary and post-depositional processes (Svirčev et al. 2013). While the process of loess formation remains to be fully understood and defined, it is certain that quasi-pedogenic and quasi-diagenetic processes have determined its present structure (Smalley and Marković 2014). Due to its high specificity, loess cannot be regarded either as a weakly consolidated sediment, soil, or rock, but as a distinct entity (Sprafke and Obreht 2016). For example, dust deposited to marine or lacustrine sediments is not loess because of the absence of the loessification process.^[1]

Microbial mats are diverse and stratified microbial biofilm communities characterized by steep gradients in light, temperature and chemical parameters. Their high optical density creates a competition for light among phototrophic microalgae and bacteria residing in the uppermost mat layers. Strategies to counter such resource limitation include metabolic investment in protective and light-harvesting pigments enabling exploitation of separate niches in terms of irradiance and spectral composition, or investment in motility to enable migration to an optimal light microenvironment.^[3]

Light-exposed coastal sediments in shallow waters and intertidal areas are often colonized by benthic microalgae and cyanobacteria, which under the absence of animal grazing (typically under environmental extremes such as desiccation, high salinity or sulfide levels) can form complex stratified microbial biofilm communities, i.e., microbial mats (Stal, 1995), that stabilize the sediment by excretion of exopolymers. Microbial mats are densely populated and highly compacted, vertically stratified microbial communities characterized by steep gradients of physical (light and temperature) and chemical parameters (Kühl et al., 1996; Dillon et al., 2009; Al-Najjar et al., 2012; De Beer and Stoodley, 2013). The uppermost layers of coastal microbial mat layers are typically dominated by diatoms on top of a dense green cyanobacterial layer that is often dominated by Microcoleus chtonoplastes and various other motile, filamentous cyanobacteria (Wieland et al., 2003; Fourcans et al., 2004; Dillon et al., 2009). Often, purple sulfur bacteria and green filamentous anoxygenic phototrophs are found below the cyanobacteria followed by a reduced black layer of precipitated iron sulfide (Jørgensen, 1982). Besides light-driven sulfide oxidation by anoxygenic phototrophs, sulfide can also be oxidized efficiently by colorless sulfur bacteria such as filamentous Beggiatoa spp. (Nelson and Castenholz, 1981) that are motile and produce white patches in the microbial mat at the oxygen-sulfide interface (Jørgensen and Revsbech, 1983).^[3]

Light is the primary energy source for photosynthetic microbial mats. Due to the high density of photopigments, organic matter, and sediment particles, light is subject to intense scattering and absorption within microbial mats (Kühl and Jørgensen, 1994; Kühl et al., 1994). This can lead to an extremely narrow photic zone (Kühl et al., 1997) and a rapid change in spectral composition with depth (Lassen et al., 1992; Cartaxana et al., 2016b). Ploug et al. (1993) related changes in light quality in a coastal microbial mat to the vertical zonation of a population of diatoms over a dense filamentous cyanobacteria layer that largely sustained their oxygenic photosynthesis via phycobiliproteins with absorption characteristics complementary to chlorophylls. Similarly, complementary use of visible and near-infrared radiation by chlorophylls/phycobilins vs. bacteriochlorophylls enables coexistence of dense populations of oxygenic phototrophs on top of anoxygenic phototrophs (Kühl and Fenchel, 2000). Apart from light, other parameters such as nutrient availability or the presence of sulfide may vertically limit photosynthesis in microbial mats (Stal, 1995; Kühl et al., 1996; Wieland et al., 2003).^[3]

The ecological success of benthic microbes in optically dense and vertically stratified communities has recurrently been linked to cell motility allowing individual microbes to search for optimal environmental conditions regarding crucial parameters such as light, temperature, O2 or nutrient availability (Whale and Walsby, 1984; Bebout and Garcia-Pichel, 1995; Bhaya, 2004; Serôdio et al., 2006). Complex migratory rhythms determined by day/night cycles, tidal regimes, UV exposure and changes in irradiance levels have been described for both diatom- and cyanobacteria-dominated phototrophic mat communities (Bebout and Garcia-Pichel, 1995; Serôdio et al., 2006; Coelho et al., 2011). Similar strategies to optimize photon capture are known in terrestrial plants, where the position of chloroplast in palisade and mesophyll layers in leaves can change depending on light levels and light field directionality, i.e., diffuse versus collimated light (Vogelmann, 1993; Gorton et al., 1999; Wada et al., 2003). Raphidic diatoms, filamentous cyanobacteria and Beggiatoa spp. are able to glide within an extracellular polymeric matrix at speeds of 0–10 μm s–1 (Glagoleva et al., 1980; Richardson and Castenholz, 1987; Hoiczyk, 2000; Gupta and Agrawal, 2007; Kamp et al., 2008; Tamulonis et al., 2011). Because of the steep light gradient, migration and the resultant vertical redistribution of the productive biomass have important consequences for both the photobiology of the phototrophs and the net primary productivity of the microbial mat ecosystem (Bebout and Garcia-Pichel, 1995; Cartaxana et al., 2016b).^[3]

Biofilms are structured microbial communities attached to surfaces, which play a significant role in the persistence of biofoulings in both medical and industrial settings. Bacteria in biofilms are mostly embedded in a complex matrix comprised of extracellular polymeric substances that provide mechanical stability and protection against environmental adversities. Once the biofilm is matured, it becomes extremely difficult to kill bacteria or mechanically remove biofilms from solid surfaces. Therefore, interrupting the bacterial surface sensing mechanism and subsequent initial binding process of bacteria to surfaces is essential to effectively prevent biofilm-associated problems.^[5]

Biofilm is a three-dimensional structure formed as a result of microorganism’s surface sensing, initial adhesion to surfaces, followed by subsequent colonization and production of an extracellular polysaccharides matrix (EPS) (Flemming et al., 2016). The development of the biofilm is a sequential process that starts with a loose association of the microorganisms to a surface then converted to strong adhesion. At the final stage of adhesion, the bacterial cell wall is deformed, which reinforces the bacteria’s adhesion toward the surface by positioning the cytoplasmic bacterial molecules closer to the surface. This enables bacteria to interact with surfaces using their bacterial surface molecules in the form of Lifshitz-van der Waals attractive forces (Carniello et al., 2018). Once the microorganisms adhere to a surface, they often aggregate and form microcolonies that maturate over time (An and Friedman, 1998). The structured channels within the biofilm facilitate the exchanges of nutrients and byproducts between the embedded microorganisms and the external environment, which attributes to the microorganisms’ colonization growth and maturation (Flemming et al., 2016). After biofilm maturation, the microorganisms shed and move from the matured biofilm to join another biofilm community or to become a pioneer of a new one (Hall-Stoodley et al., 2004).^[5]

A significant feature of the biofilm is that it can form either on a biotic or abiotic surface. Thus, it is deeply associated with a diverse spectrum of industrial biofouling as well as human health problems, such as dental caries, infective endocarditis, cystic fibrosis pneumonia, and peritoneal dialysis catheters infection (Hall-Stoodley et al., 2004). Particularly, 60–70% of all healthcare-associated infections are attributed to biofilm infections in implantable medical devices (Bryers, 2008), thereby it is imperative to develop novel anti-infectious biomaterials. Biofilm formation is essential for microorganisms’ survival since it benefits bacteria; it stimulates bacterial growth and acts as a barrier that protects the embedded microorganisms from environmental challenges and administered antimicrobials (Lebeaux et al., 2014). During the biofilm maturation, the EPS matrix enhances cell adhesion and cohesion that promote both microbial accumulation onto a surface and the development of densely packed cell aggregates, resulting in a highly structured and adherent biofilm. As such, once biofilms are established, it becomes extremely difficult to kill embedded bacteria or mechanically remove biofilms from surfaces. Therefore, interrupting the bacterial surface sensing mechanism and their initial binding process to surfaces is essential to effectively prevent biofilm-related problems.^[5]

Highlighting that biofilm formation is initiated by bacterial adhesion to a surface, bacterial sensing and responding to surfaces have been widely studied. There are many factors affecting the process of bacterial adhesion to a surface; duration of exposure of bacteria to surfaces, population of inoculated bacteria, bacterial characteristics (e.g., cell wall components, appendages, and motility), and type/richness of nutrients could affect. Surface properties of the substrate, such as surface charge density, wettability, roughness, stiffness, and surface topography are also considered important factors governing initial bacterial adhesion to surfaces (as illustrated in Figure 1) (An and Friedman, 1998; Song et al., 2015; Carniello et al., 2018; Li et al., 2019; Chien et al., 2020). From that aspect, there were many attempts to explain the mechanism of bacterial binding to surfaces using physicochemical approaches such as thermodynamic theory, Lifshitz-van der Waals, and electrostatic-double layer interactions (Carniello et al., 2018). On the other hand, various strategies have been developed to prevent biofilm formation at an early stage, either by engineering anti-adhesive surface properties or introducing antibacterial elements to a surface (Zhang et al., 2018; Chi et al., 2019; Li et al., 2019).^[5]

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Draft articles.... not for citation

Boom and bust fisheries

Recent models in theoretical physics predict that swarming animals share certain properties at the group level, regardless of the type of animals in the swarm.^[1]

Collective behaviours of living systems occur on many different scales^[2] including flocks of birds,^[3] schools of fish,^[4] swarms of insects or bacteria,^[5][6] herds of quadrupleds,^[7] stampedes of people,^[8][9] robotic swarms^[10] and molecular motors.^[11][12] "It turns out that the collective properties of such systems seem to be quite robust and universal. Accordingly, this field attracted the interest of the statistical physics community with the challenge of introducing minimal models that could capture the emergence of collective behaviour."^[13]

Locust swarming

"One key prediction is that as the density of animals in the group increases, a rapid transition occurs from disordered movement of individuals within the group to highly aligned collective motion. Understanding such a transition is crucial to the control of mobile swarming insect pests such as the desert locust. We confirmed the prediction of a rapid transition from disordered to ordered movement and identified a critical density for the onset of coordinated marching in locust nymphs. We also demonstrated a dynamic instability in motion at densities typical of locusts in the field, in which groups can switch direction without external perturbation, potentially facilitating the rapid transfer of directional information."^[1]

Bird flocks

Bhattacharya and Vicsek (2010) used an SPP model to analyse what happens when a collective behaviour in a group of people or animals starts or stops. They found that flocks of birds make sudden simultaneous changes of course and also make unanimous decisions when to land. The decisions that are made depend on where the birds are in the flock.^[14] According to Bhattacharya, "In the absence of a decision-making leader, the collective shift to land is heavily influenced by the perturbations that the individual birds are subject to, such as the bird's flying position within the flock."^[15] The model could also be applied to a swarm of unmanned aeroplanes, to initiating a desired motion in a crowd of people, or to interpreting group patterns when stock market shares are brought or sold.^[15]

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• Bertin E, Droz M an Grégoire G (2009) [ "Hydrodynamic equations for self-propelled particles: microscopic derivation and stability analysis"] J. Phys. A, 42(44): paper 445001. doi:10.1088/1751-8113/42/44/445001
• Czirók A, Stanley HE and Vicsek T (1997) "Spontaneously ordered motion of self-propelled particles" Journal of Physics A, 30(5): paper 1375. doi:10.1088/0305-4470/30/5/009
• Czirók A, Barabási AL and Vicsek T (1999) "Collective motion of self-propelled particles: Kinetic phase transition in one dimension" Phys Rev Lett, 82(1): 209–212.
• Czirók A and Vicsek T (2001) "Flocking: collective motion of self-propelled particles" In: Vicsek T Fluctuations and scaling in biology, Oxford University Press, pp. 177–209. ISBN 9780198507901.
• Czirók A and Vicsek T (2006) "Collective behavior of interacting self-propelled particles" Physica A, 281: 17–29. doi:10.1016/S0378-4371(00)00013-3
• D'Orsogna MR, Chuang YL, Bertozzi AL and Chayes LS (2006) "Self-propelled particles with soft-core interactions: patterns, stability, and collapse" Phys Rev Lett, 96(10): paper 104302.
• Levine H, WJ Rappel WJ and Cohen I (2001) "Self-organization in systems of self-propelled particles" Physical Review E, 63: paper 017101.
• Mehandia V and Nott PR (2008) "The collective dynamics of self-propelled particles" Journal of Fluid Mechanics, 595: 239–264. doi:10.1017/S0022112007009184
• Simha RA and Ramaswamy S (2006) "Hydrodynamic fluctuations and instabilities in ordered suspensions of self-propelled particles" Phys Rev Lett, 89(5): paper 058101. doi:10.1103/PhysRevLett.89.058101
• Sumpter DJT (2010) Collective Animal Behavior Chapter 5: Moving together. Princeton University Press. ISBN 9780691129631.
• Vicsek T (2010) "Statistical physics: Closing in on evaders" Nature, 466: 43–44. doi:10.1038/466043a
• Yates CA (2007) "On the dynamics and evolution of self-propelled particle models" MSc thesis, Somerville College, University of Oxford.
• Yates CA, Baker RE, Erban R and Maini PK (2010) "Refining self-propelled particle models for collective behaviour" Oxford Centre for Collaborative Applied Mathematics, Report Number 09/46.

In the natural world, animals often gather together because there is some safety in numbers.

"Why do fish swim in schools? First and foremost, schools protect fish from enemies. It's the same rule our mothers taught us, always stay in a group because there is safety in numbers. Predators find it easier to chase down and gobble up a fish swimming all alone, than trying to cut out a single fish from a huge group. The same holds true in reverse. Fish can better defend their territory in a group. Bullies will think twice about facing an angry school of fifty fish."

It is a similar behaviour to animals that socialize in herds/birds that flock together.

Fr ́eon, P. and O.A. Misund, Dynamics of pelagic fish distribution and be- havior: e ects on fisheries and stock assessment. Fishing new books (1999).

"The current level of bicycling in a community also affects bicycling safety and the potential to further increase bicycling. Several studies have demonstrated the principle of “safety in numbers.” Using both time-series and cross-sectional data, the studies find that bicycling safety is greater in countries and cities with higher levels of bicycling, and that bicycling injury rates fall as levels of bicycling increase. As the number of cyclists grows, they become more visible to motorists, which is a crucial factor in bicycling safety. In addition, a higher percentage of motorists are likely to be bicyclists themselves, and thus more sensitive to the needs and rights of bicyclists. The presence of large numbers of bicyclists may also help underpin their legal use of roadways and intersection crossings and generate public and political support for more investment in bicycling infrastructure."(^[1][2][3])^[4]

^[5]

However, the noted cycling activist John Forester...

The term safety in numbers can be applied to any situation where there is an inverse relationship between the number of participants in some given activity and the individual danger encountered by those participants. In road safety, the classic example is Smeed's law, first demonstrated in 1949 by Smeed. According to this law, in any given geographical region there is an inverse relationship between the number of motorists on the road and the likely of an individual motorist being killed.

Situations where there are safety in numbers can be contrasted with situations where there can be dangers in numbers. For example:

fish that school for safety may be attacked by larger fish that school together so they can predate more efficiently.

Armies that mass to confront each other present a danger in numbers.

... a form of collective animal behavior

"1. a phenomenon in which aquatic predators, esp sharks, become so excited when eating that they attack each other 2. a period of intense excitement over or interest in a person or thing: the media erupt into a feeding frenzy "^[1]

": a frenzy of eating; also : the excited pursuit of something by a group"^[2]

A feeding frenzy refers to the highly aroused "pursuit of something by a group".^[3] The term was first used in a book in 1958 by V.M. Coppleson in the context of frenzied sharks attacks.^[4][5] However, sharks are not the only animals to trigger into feeding frenzies. Animals as various as lions, seabirds and alligators can go into frenzied states where they compete wildly for some food item.^[6] Organisms that engage in feeding frenzies can be as large as humpback whales and as small as bacteria. By extension, the term "feeding frenzy" has come to be used "to describe everything from brides-to-be at a designer wedding dress sale to attack journalists hungry for a scandalous ratings-buster of a story".^[7][8]

"A single locust or a single bird is hardly the basis for fear, but a feeding frenzy is horrifying–in history and in cinema. In an entomological version of Alfred Hitchcock's The Birds, which scared the bejeezus out of moviegoers a century later...."^[9]

Feeding frenzies are widespread among marine animals.

"Marine animals of different kinds, preying on species occurring in swarms or schools, are thrown into a state of extreme excitation by catching one comparatively small prey. The feeding frenzy thus induced makes sharks snap at the most inappropriate objects, and the same response in tuna is exploited by commercial fishermen: after having snapped up a few pieces of bait, these fish will snap blindly at unbaited hooks."^[10]

"A shark feeding frenzy occurs when a number of sharks fight for the same prey. Sharks are usually solitary diners, and a feeding frenzy indicates why that might be. To an observer, it looks like the sharks lose their mind biting at anything that's in their way in an uncontrollable rage. They thrash around, their snouts elevating and their backs arching, all signs that indicate an impending attack. Some accounts tell of sharks eating each other and of sharks continuing to feed even after they've been disemboweled by other sharks [sources: Encyclopedia Britannica, Martin]".^[8]

causes

"But what causes these feeding frenzies? Some studies indicate that sharks will always be motivated to eat, no matter how full they are [source: Parker]. Does this mean that a feeding frenzy could happen at any moment? What causes them to get so crazed? And why can't they just share?"^[8]

"Some scientists have observed feeding frenzies occurring naturally, particularly in shallow waters where seabirds, seals and sea lions congregate. However, they don't appear to be a common natural occurrence. Rather, it's more likely that feeding frenzies are rare events caused by a "supernormal stimulus," such as a high amount of stress in the water [source: Parker]."^[8]

"Studies have shown that sharks can sense distressed prey; they respond to scents emitted by injured fish, and they can hear the sounds of a wounded person thrashing around in the water [source: Shark Trust]. Given the choice between healthy and injured prey, the shark will always pick the injured prey because it will take less energy to catch it. But things get crazy when more than one shark shows up to take advantage of the prey's misfortune."^[8]

"It's important to note that many species retain a sense of order within a frenzy. The Caribbean reef shark, for example, still maintains a quasi pecking order during a feeding frenzy [source: Dehart]. The whitetip reef shark also behaves in a (somewhat) orderly fashion during what looks to be a chaotic bloodbath. If this buffet entices multiple sharks, sometimes they'll inadvertently bite each other [source: Dehart]."^[8]

"Many feeding frenzies start near fishing boats, particularly when fishermen pull in a net of fish. These fish are thrashing against the net and perhaps have been injured in their capture, and the chemicals they give off attract the sharks. Sharks become aroused by the scent of blood and think they've happened upon an easy meal, but when more than one shark shows up, the scene gets competitive."^[8]

"In the case of a shipwreck, sharks may be attracted to the panicking humans who are splashing around in the water. At the time of World Wars I and II, the oceanic whitetip shark was believed to have had many a feeding frenzy when boats were torpedoed and planes were shot down. This deep-water dwelling shark was often first on the scene of maritime disasters, such as the World War II sinking of the Nova Scotia steamship. Of the 1,000 men aboard, only 192 survived, with many fatalities ascribed to whitetip feeding frenzies [source: Bester]."^[8]

"Humans aren't normally on the shark's menu. Shark attacks on humans might actually just be an error or an experimental bite to determine how they'd taste. But one practice that is increasingly causing feeding frenzies may lead sharks to associate humans with food even more. Shark feeding dives, an activity in which a group of caged divers descends to the deeps to get up close and personal with sharks, have become a huge draw in some parts of the world. To attract the sharks, diving companies use chum, or a mixture of blood and dead fish bits. Now, frenzies are seen most often when sharks are fed with artificial bait [source: Parker]."^[8]

"Whether the attraction is to frantic prey or a frothy mix of blood and guts, the intense stress emitted by these items seems to cause the sharks to freak out and enter the frenzied state. The more sharks attracted to the scene, the more distressed the scene becomes, as the splashing increases. Scientists don't know yet how much of a feeding frenzy is actually about eating and how much of it is about establishing dominance in some ordered way that looks like chaos to us. Regardless, frenzies are one more thing that makes sharks both fearsome and fascinating."^[8]

examples

"Although several great white sharks may be drawn to the smell of blood, they rarely, if ever, have a feeding frenzy."^[6]

The oceanic whitetip shark is an aggressive but slow-moving fish dominates feeding frenzies, and is a danger to shipwreck or air crash survivors.^[11] These sharks often form groups when individuals converge on a food source, whereupon a feeding frenzy may occur. This seems to be triggered not by blood in the water or by bloodlust, but by the species' highly strung and goal-directed nature (conserving energy between infrequent feeding opportunities when it is not slowly plying the open ocean). The oceanic whitetip is a competitive, opportunistic predator that exploits the resource at hand, rather than avoiding trouble in favor of a possibly easier future meal.^[12]

Sharks usually swim alone. However, sometimes a group of sharks have a feeding frenzy, attacking and eating everything around them. Feeding frenzies usually start when sharks smell blood.

Excited Galapagos sharks are not easily deterred; driving one away physically only results in the shark circling back while inciting others to follow, whereas using weapons against them could trigger a feeding frenzy.^[13]

Similar to the grey reef shark, the blacktip reef shark becomes more excited and "confident" in the presence of other individuals of its species, and in extreme situations can be roused into a feeding frenzy.^[14] Unlike blacktip reef sharks and grey reef sharks, whitetip reef sharks do not become more excited when feeding in groups and are unlikely to be stirred into a feeding frenzy.^[14] In the presence of a large quantity of food, grey reef sharks may be roused into a feeding frenzy; in one documented frenzy caused by an underwater explosion that killed several snappers, one of the sharks involved was attacked and consumed by the others.^[15]

Like blacktip sharks, Spinner sharks congregate around shrimp trawlers to feed on the discarded bycatch, and may be incited into feeding frenzies.^[13]

---

"Sharks circle their prey, disconcertingly appearing out of nowhere and frequently approaching from below. Feeding behaviour is stimulated by numbers and rapid swimming when three or more sharks appear in the presence of food; activity progresses from tight circling to rapid crisscross passes. Under strong feeding stimuli, excitement can intensify into a sensory overload that may result in cannibalistic feeding, or “shark frenzy,” in which injured sharks, regardless of size, are devoured."^[16]

"Under strong feeding stimuli, the sharks’ excitement may intensify into what is termed a feeding frenzy, possibly the result of stimulatory overload, in which not only the prey but also injured members of the feeding pack are devoured."^[17]

"Experiments on several species of large sharks indicate that they do discriminate food types—preferring tuna, for example, to other fish species. Under some conditions, however, they become less fastidious, going into a feeding frenzy in which they attack anything, including others of their own kind."^[18]

---

"When a lot of food is suddenly available to a group of hungry sharks, such as when people dump garbage into the water, some species, particularly highly social requiem sharks, may become very excited and crowd around to eat. The action can become very hectic when there are lot of sharks competing for food. Sensory information–sound, sight, touch, and electrical sense–can build up and overwhelm the shark's normal inhibitions. The result is a feeding frenzy, during which the animals can seriously injure one another."^[6]

From Oceanic whitetip shark:

"Groups often form when individuals converge on a food source, whereupon a feeding frenzy may occur. This seems to be triggered not by blood in the water or by bloodlust, but by the species' highly strung and goal-directed nature (conserving energy between infrequent feeding opportunities when it is not slowly plying the open ocean). The oceanic whitetip is a competitive, opportunistic predator that exploits the resource at hand, rather than avoiding trouble in favor of a possibly easier future meal.^[12]"

From Spinner shark

"Like blacktip sharks, they congregate around shrimp trawlers to feed on the discarded bycatch, and may be incited into feeding frenzies.^[13]

From Blacktip shark

"The excitability and sociability of blacktip sharks makes them prone to feeding frenzies when large quantities of food are suddenly available, such as when fishing vessels dump their refuse overboard.^[13]"

shark links

• Alevizon, William The Florida Fish-Feeding Frenzy: Background, Issues, and a Wake-Up Call Cyber Diver News Network. DEAD
• Allen, Thomas B Shark Protection: Why Do Sharks Attack? Gorp, 12 May 2008.
• Auerbach, Paul S Shark Attacks International Society of Travel Medicine, Newsletter, March–April 2002. DEAD
• Bester, Cathleen Oceanic Whitetip Shark Florida Museum of Natural History, Ichthyology Department.
• Dehart, Andy. Personal Correspondence. July 17, 2008.
• Carrier, Jeffrey C. "Shark." Microsoft Encarta Online Encyclopedia. 2007. (May 12, 2008)

http://encarta.msn.com/encyclopedia_761552860/Shark.html DEAD

• "Feeding frenzy: When sharks attack." BBC News E-cyclopedia. Jan. 30, 2001. (May 12, 2008)

http://news.bbc.co.uk/2/hi/special_report/1999/02/99/e-cyclopedia/ 1142956.stm

• Leniuk, Darryl. "Front row at a feeding frenzy." The Globe and Mail. Nov. 12, 2005. (May 12, 2008)

http://www.theglobeandmail.com/servlet/story/LAC.20051112.SHARK12 /TPStory/specialTravel

• Martin, R. Aidan. "Do Sharks Feel Pain?" ReefQuest Centre for Shark Research. (May 12, 2008)

http://www.elasmo-research.org/education/topics/s_pain.htm

• Parker, Steve and Jane. "The Encyclopedia of Sharks." Firefly Books. 2002.
• Ritter, Erich K. "Shark attacks - an ever intriguing puzzle." Shark Info. (May 12, 2008)

http://www.sharkinfo.ch/SI2_98e/attacks1.html

• "Senses of Sharks." Shark Trust. 2007. (May 14, 2008)

www.sharktrust.org/do_download.asp?did=27360 DEAD but other articles available

• Shark Encyclopædia Britannica Online, 2012. Retrieved 6 May 2012.

Chemical senses, such as smell and taste, can play an important role in the feeding behaviour of fishes. For centuries, fishermen have used bait fish and chumming techniques, such as tossing live sardines constrained in a net into the water, to arouse and attract fish. The chemical signals emitted from the bait fish can powerfully excite predator fishes, triggering in some a feeding frenzy.^[19] Visual senses can also be important. Swarms of insects flying low over the water, such as mayflies, can trigger feeding frenzies in trout.^[20][21] When a fish school goes into a feeding frenzy, the fish can strike pretty much anything thrown into their midst, and it can become very easy for fishermen to catch them. Live bait thrown into the water among skipjack tuna can cause the fish to go into a feeding frenzy where they bite anything, including barbless and baitless hooks from fishing poles (see the video on the right).

Similarly, forage fish can go into feeding frenzies when plenty of food is available. Filter feeders, like herrings and anchovies, which feed largely on larger plankton such as copepods, can go into feeding frenzies when they swim into a cloud of copepods, perhaps as "an adaptation to exploit as much as possible of a patch of large particles as quickly as possible". ^[22]

Each spring, some fishes such as herring and capelin deposit huge amounts of eggs in shallow water on the sea bottom. Such mass spawnings can trigger feeding frenzies in other species, lasting for days. Gulls and kittiwakes, seals and sea lions, and fishes and crabs gather to gorge and feast on the mass of eggs.^[23]

Piranha have a fearsome, but not altogether deserved reputation for ferocious feeding frenzies.

"When Theodore Roosevelt went on a hunting expedition in Brazil in 1913, he got his money's worth. Standing on the bank of the Amazon River, he watched piranhas attack a cow with shocking ferocity. It was a classic scene: water boiling with frenzied piranhas and blood, and after about a minute or two, a skeleton floating to the suddenly calm surface."^[24]

"Roosevelt was horrified, and he wrote quite a bit about the vicious creatures in his 1914 book, "Through the Brazilian Wilderness." He recounted the stories of townspeople who had been eaten alive, and others who'd lost body parts to piranhas while bathing in the river. "They are the most ferocious fish in the world," Roosevelt announced to the world. "[T]hey will snap a finger off a hand incautiously trailed in the water; they mutilate swimmers -- in every river town in Paraguay there are men who have been thus mutilated; they will rend and devour alive any wounded man or beast; for blood in the water excites th­em to madness" [source: ESPN]. The legend of the piranha had begun."^[24]

"Hollywood picked it up from there with the 1978 horror flick "Piranha" ("When flesh-eating piranhas are accidentally released into a summer resort's rivers, the guests become their next meal"), 1981's "Piranha II: The Spawning," and a remake of the original B-movie due out sometime in 2008 [sources: IMDb, Movie Insider]. The killer piranha has transitioned to the 21st century with even more gore."^[24]

"But is the vicious reputation deserved? Roosevelt witnessed the now-famous cow stripping incident in Brazil, where piranhas live in especially high numbers. Howev­er, they're native to and pretty common all along South America's Amazon River -- from Argentina to Colombia. So are South American bovines a regular meal for these ferocious fish? And why are there cows hanging out in the Amazon River?^[24]

"Roosevelt explored the exotic Brazilian Amazon as an avid hunter, but he wasn't exactly the common tourist. He was a former U.S. president, and his guides wanted him to be very pleased with his trip. But what he saw was real: piranhas stripping a cow to the bone in a shockingly short period of time. Whether it was really under a minute, we'll never know. But we do know that this type of attack is feasible for piranhas. What Roosevelt witnessed had some special circumstances, which we'll get to later. Nonetheless, it was a disturbing sight, considering the size of these fish."^[25]

"We're not talking monsters here. While piranhas top out at about 2 feet (60 cm), most are about 8 inches (20 cm) from head to tail and weigh just a few pounds. The most vicious of the roughly 20 species found in the Amazon River, the red-bellied piranha (Pigocentrus naterreri), is on the small end of the spectrum and usually weighs about 3 pounds (1.36 kg) [source: ESPN]. The next most aggressive species is the black piranha, (Serrasalmus rhombeus), which tends to be bigger than the red-bellies."^[25]

"A piranha's teeth are only about a quarter-inch (4 mm) long, but they're like razors, and the whole jaw mechanism is designed for chomping efficiency. The teeth are spaced in an interlocking pattern, so when a piranha jaw snaps shut, the top teeth and the bottom teeth interlace like dozens of razor-sharp scissors. The jaws are incredible strong: Some people who have lost toes to piranhas have actually lost the entire toe, bone included."^[25]

"The reason why piranhas can strip a large animal like a cow down to a skeleton so quickly is because of a few factors. First, piranhas don't chew. When they bite down, the big chunk of flesh they take out of the cow goes right into their bellies. They just keep snapping their jaws shut and filling themselves up. Next, that type of task is accomplished by hundreds of piranhas, not just the typical school size of 20, and piranhas are very efficient team eaters. In a feeding frenzy, they rotate continuously, so as each piranha takes a bite, it moves out of the way so the piranha behind it can get a bite, and so on. They take turns with incredible speed, which is where the boiling-water effect comes from. The piranhas are constantly changing position during a feeding frenzy."^[25]

"Another important factor involved when piranhas eat a large animal in minutes has to do with the special circumstances surrounding what Roosevelt saw: Feeding frenzies happen when piranhas are starving. It's not an everyday occurrence. Roosevelt's guides in Brazil had set up the scene for their famous guest. They had set nets to close off a small part of the river and had tossed hundreds of piranhas into it, trapping them. By the time they threw that cow into the water, the piranhas had been starving for some time."^[25]

| "Attacking a live animal isn't out of the question for piranhas, but it's not likely they could take down a healthy, full-grown human. They have, however, been known to attack sickly, old animals that come to drink from the river. When a cow lowers its head, they'll clamp onto its face. If the cow is too weak to fight back, the piranhas will drag it into the water and eat it. But live prey isn't the mainstay of their diet. Mostly, they're scavengers. The skeletons of animals and people found in the Amazon, apparently eaten by piranhas, weren't attacked alive. They were already dead when the piranhas got to them."^[26]

"As with other fish, mammals are by no means a big part of the piranha's diet. They eat other fish, mostly, and sometimes other piranhas. An aquarium in Wales that had gone to considerable trouble to acquire a male and a female piranha (piranhas are illegal to import in most parts of the world, including Britain) in hopes the two would mate, were disappointed when the female ate her potential suitor [source: BBC News]. But piranhas aren't strict carnivores. They'll eat fruits and plants, too, especially when they're young."^[26]

"Contrary to legend, most piranhas don't really attack anything. Twelve of the 20 species in the Amazon survive entirely on taking small bites out of the fins and scales of other fish as they pass by. The fish swim away only slightly disturbed, and their fins and scales grow back."^[26]

"While piranhas aren't quite the vicious man-eaters of myth, attacks on humans have been increasing in frequency. In South America, people have been losing fingers and toes more often than they were just 10 years ago, and experts believe it might have something to do with an increase in the number of dams on the Amazon River. Dams slow the current, and piranhas like to breed in the slowest-moving waters. Creating more placid areas along the river is an invitation to piranhas to come set up camp in large numbers. Since placid areas also attract swimmers, humans and piranhas are coming into contact more and more."^[26]

piranaha links

• China orders piranhas destroyed. BBC News. December 24, 2002.

http://news.bbc.co.uk/2/hi/asia-pacific/2603689.stm

• Hungry piranha seeks good catch. BBC News. June 1, 2000.

http://news.bbc.co.uk/2/hi/uk_news/wales/772802.stm

• Piranha. Encyclopedia Britannica.

http://search.eb.com/eb/article-9060157

• Piranha. Extreme Science.

http://www.extremescience.com/Piranha.htm

http://animals.howstuffworks.com/fish/piranha-info.htm

• Piranha increase "due to dams". BBC News. December 28, 2003.

http://news.bbc.co.uk/1/hi/sci/tech/3346301.stm

• Piranhas. London Aquarium.

http://www.londonaquarium.co.uk/files/factsheets/Piranhas.pdf

• Rumble in the jungle with Amazon's killer piranha. LA Times. November 22, 2005.

http://travel.latimes.com/articles/la-os-piranha22nov22

• Sutton, Keith "Catfish." Out there: Piranha! ESPN.com.

http://sports.espn.go.com/outdoors/tv/columns/story?columnist=sutton_keith&page=g_col_sutton_piranha

• The Truth About Piranha Attacks. Practical Fishkeeping.

http://www.practicalfishkeeping.co.uk/pfk/pages/item.php?news=1180

One of the world's great feeding frenzies occurs most years between May and June when millions of sardines spawn in the cool waters of the Agulhas Bank and move northward along the east coast of South Africa. Their sheer numbers create a feeding frenzy along the coastline. The run, containing millions of individual sardines, occurs when a current of cold water heads north from the Agulhas Bank up to Mozambique where it then leaves the coastline and goes further east into the Indian Ocean.

From Sardine run:

"The sardine run of southern Africa occurs from May through July when billions of sardines – or more specifically the Southern African pilchard Sardinops sagax – spawn in the cool waters of the Agulhas Bank and move northward along the east coast of South Africa. Their sheer numbers create a feeding frenzy along the coastline. The run, containing millions of individual sardines, occurs when a current of cold water heads north from the Agulhas Bank up to Mozambique where it then leaves the coastline and goes further east into the Indian Ocean."

From Bait ball

"Their sheer numbers create a feeding frenzy along the coastline . "

From Forage fish

"dolphins, tuna, sailfish, Cape fur seal s and even killer whales congregate and follow the shoals, creating a feeding frenzy along the coastline."

From Shoaling and schooling

"dolphins, tuna, sailfish, Cape fur seal s and even killer whales congregate and follow the shoals, creating a feeding frenzy along the coastline"

From The Blue Planet

"A feeding frenzy is shown, as striped marlin , tuna and a Sei whale pick off a shoal of sardines until all within it have been consumed. ... "

From Swarm behaviour

krill: "extremely vulnerable to predators Dense swarms may elicit a feeding frenzy among fish, birds and mammal predators, especially near the surface. ... "

Humboldt squid are large carnivorous marine invertebrates that move in schools of up to 1,200 individuals. They swim at speeds of up to 24 kilometres per hour (15 mph (13 kn)^*) propelled by water ejected through a siphon and by two triangular fins. Their tentacles bear suckers lined with sharp teeth with which they grasp prey and drag it towards a large, sharp beak. During the day the Humboldt squid are mesopelagic fish, living at depths of 200 to 700 m (660 to 2,300 ft). Electronic tagging has shown that they also undergo diel vertical migrations which bring them closer to the surface from dusk to dawn.^[27] They hunt near the surface at night, taking advantage of the dark to use their keen vision to feed on more plentiful prey. The squid feed primarily on small fish, crustaceans, cephalopods, and copepod, and hunt for their prey in a cooperative fashion, the first observation of such behaviour in invertebrates.^[28] The Humboldt squid is also known to quickly devour larger prey when cooperatively hunting in groups. Humboldt squid are known for their speed in feasting on hooked fish, sharks, and squid, even from their own species and shoal,^[29] and have been known to attack fishermen and divers.^[30] Their colouring and aggressive reputation has earned them the nickname diablos rojos (red devils) from fishermen off the coast of Mexico as they flash red and white when struggling with the fishermen.^[31]

Most krill, small shrimp-like crustaceans, form large swarms, sometimes reaching densities of 10,000–60,000 individual animals per cubic metre.^[32][33][34] Swarming is a defensive mechanism, confusing smaller predators that would like to pick out single individuals. Krill typically follow a diurnal vertical migration. Until recently it has been assumed that they spend the day at greater depths and rise during the night toward the surface. It has been found that the deeper they go, the more they reduce their activity,^[35] apparently to reduce encounters with predators and to conserve energy. Later work suggested that swimming activity in krill varied with stomach fullness. Satiated animals that had been feeding at the surface swim less actively and therefor sink below the mixed layer.^[36] As they sink they produce faeces which may mean that they have an important role to play in the Antarctic carbon cycle. Krill with empty stomachs were found to swim more actively and thus head towards the surface. This implies that vertical migration may be a bi- or tri-daily occurrence. Some species form surface swarms during the day for feeding and reproductive purposes even though such behaviour is dangerous because it makes them extremely vulnerable to predators.^[37] Dense swarms may elicit a feeding frenzy among fish, birds and mammal predators, especially near the surface. When disturbed, a swarm scatters, and some individuals have even been observed to moult instantaneously, leaving the exuvia behind as a decoy.^[38]

Plankton blooms...

"Diatom blooms in spring".^[39]

"The little, ferociously abundant diatoms_marine algae with shells of silica_bloom in the spring just like plants on land. Traditionally this has marked the beginning of a spring feeding and breeding frenzy in the ocean." ^[40]

Quadrupeds, such as lions, wolves and alligators

" A single locust or a single bird is hardly the basis for fear, but a feeding frenzy is horrifying– in history and in cinema. In an entomological version of Alfred Hitchcok's The Birds, which scared the bejeezus out ofmoviegoers a century later, Sully matter-of-factly reported, "....."^[41]

Many insects also indulge in feeding frenzies. The term locust refers to the swarming phase of the short-horned grasshoppers of the family Acrididae. Normally grasshoppers ignore each other, but some species breed rapidly under suitable conditions and subsequently become gregarious and migratory. They form bands as nymphs and swarms as adults—both of which can travel great distances, rapidly stripping fields and greatly damaging crops. They eat flowers and other plants, as well as other insects including other locusts. The largest swarms can cover hundreds of square miles and contain billions of locusts. A locust can eat its own weight (about 2 grams) in plants every day. That means one million locusts can eat about one ton of food each day, and the largest swarms can consume over 100,000 tonnes each day.^[42]

Swarming in locusts has been found to be associated with increased levels of serotonin which causes the locust to change colour, eat much more, become mutually attracted, and breed much more easily. Researchers propose that swarming behaviour is a response to overcrowding and studies have shown that increased tactile stimulation of the hind legs or, in some species, simply encountering other individuals causes an increase in levels of serotonin. The transformation of the locust to the swarming variety can be induced by several contacts per minute over a four-hour period.^{[43][44][45][46]}

An individual locust's response to a loss of alignment in the group appears to increase the randomness of its motion, until an aligned state is again achieved. This noise-induced alignment appears to be an intrinsic characteristic of collective coherent motion.^[47]

"“During the peak of the nectar flow, a good, strong colony can gain 10 to 20 pounds in one day,” he says. “In Maryland, that goes on for a few weeks in late spring, and then, suddenly, it’s over.” For the remainder of the year, the weight of the hive dwindles as bees sustain themselves on the honey and pollen they have stockpiled during their three-to-four-week feeding frenzy. "^[48]

Alfred Hitchcock "The Birds"

http://books.google.co.nz/books?id=swJWsR5CFu0C&pg=PA13&dq=%22feeding+frenzy%22+locust&hl=en&sa=X&ei=rAmlT_WDLILKmQXVsuXhBA&ved=0CEMQ6AEwAA#v=onepage&q=%22feeding%20frenzy%22%20locust&f=false

The "tomato russet mite, Aculops lycopersici, vectors viruses. [and] goes into a feeding frenzy called "solanum stimulation", where it feeds until it kills its own host."^[49]

algal blooms as feeding frenzy

feeding frenzy among fungi on dead wood at the end of the Permian [9]

"When a large amount of organic matter, such as manure, is introduced into a water body (eg,a direct discharge), the microbial population quickly responds with a “feeding frenzy.” This quickly degrades the organic matter and reduces dissolved oxygen content in the affected " [10]

"Compost forms in much the same way whether in the woods or in a processing facility. In the presence of enough carbon,nitrogen, and water, microorganisms will go into a feeding frenzy that generates..." [11]

"Short-term increases in microbial respiration can be fueled by a sudden change in soil water potential, which causes microbes to either accept a rapid influx of soil water (which can lead to cell wall collapse), or to release intracellular solutes to maintain osmotic pressure which, in extreme cases, can lead to complete cell lysis. The surviving soil microbes undergo a “feeding frenzy” by capitalizing on the greater substrat" [12]

"Short-term increases in microbial respiration can be fueled by a sudden change in soil water potential, which causes microbes to either accept a rapid influx of soil water (which can lead to cell wall collapse), or to release intracellular solutes to maintain osmotic pressure, which in extreme cases can lead to complete cell lysis. The surviving soil microbes undergo a ‘feeding frenzy’ by capitalizing on the greater resource supply. This activity takes place in the span of a few hours to 2 days" [13]

"The diverse heterotrophic dinoflagellates (Pyrrhophyta) include free-living estuarine species that demonstrate pro- nounced chemosensory “ambush-predator” behavior toward algal, protozoan, or fish prey (Spero and Moree 1981; Spero 1982; Ucko et al. 1989; Burkholder et al. 1995a,b, 1997~; Landsberg et al. 199.5).This behavioral pattern apparently is widespread; thus far, it has been reported from the Mediter- ranean Sea, the Gulf of Mexico, and the western Atlantic. In each case the feeding activity has been strikingly similar: the dinoflagellates swarm up from benthic dormant cysts when they chemically detect the prey’s presence. They devour the prey-described in one case as being ripped apart in a “Feeding frenzy” (Spero and Moree 1981)-and then rapidly re-encyst. [14]

Yeast, like all living things, needs fout things to survive–warmth, moisture, foos and oxygen. Warmth is provided in several ways. Warm liquid is often used to wake up, or activate, the yeast, and the mixing and kneading processes generate additional warmth. The final warmth, the oven's heat, results in a feeding frenzy–the last burst of e=nergy that propels the load upward (known as oven spring)."^[50]

As nutrients like crop fertilisers drain into the sea, "the glut of nutrients pushes the phytoplankton into an orgy of eating and reproducing. There the mass of plant bodies supplies a second feeding frenzy, among the sea's bacteria, which produce vast quantities of methane, nitrous oxide, and sometimes, as oxygen is depleted, hydrogen sulfide as waste products. Most of the plankton generated methane remains in nthe water because the surface and the deeps of the sea are separated into layers that are hard to mix ... If the store of deep-sea methane should ever breach the surface–think mof a nasty belch–it would release a termedous amount of methane into the atmosphere. Methane is a far more potent greenhouse gas the carbon dioxide.^[40]

Microorganisms, such as bacteria, also engage in feeding frenzies. For example, "plaque contains bacteria which feed on carbohydrates in the mouth. As a result of their feeding frenzy, the bacteria produce acids which can attack the tooth enamel–the outermost layers of the tooth. If the plaque isn't removed, it continues to build, creating more acid that continues to damage the tooth enamel."^[51]

In turn, bacteria can be the target of feeding frenzies by other organisms. For example, "environmental bacteria are an integral part of microbial food webs and, as such, are constantly confronted with a range of predators and parasites, such as protozoa and phages. Consumption by protozoa is considered to be a major source of bacterial mortality in most soil, freshwater and marine ecosystems [5]. Due to their mobility, small size and generally high abundance, protozoa can track down ‘hot spots’ of bacterial growth even in the sparse vastness of the oligotrophic ocean or the narrowest soil crevices, leaving bacteria few environments in which they do not face protozoan attack and consumption."^[52]

"This high efficiency means that super- massive black holes in a feeding frenzy are the most powerful known sources of energy: They can literally outshine the entire galaxy in which they live."^[53]

From Money bag

"A money bag can be road debris after it falls out of an armored truck,^[54] causing a traffic accident^[55] or mass hysteria often compared to a feeding frenzy, as people rush to pick up "free" money.^[56]"

Within the last 20 years, once prolific mangrove forests and seagrassbeds, which absorb massive amounts of nutrients and sediment, have been destroyed. The loss of wetlands, mangrove habitats and seagrassbeds affect the water quality of inshore reefs.^[1]

Global losses of mangrove forests over the past few decades exceed 35 percent.^[2]

Nurseries for juvenile coral reef fish are often found inhabiting mangroves.^[3][4] emblages across an estuarine gradient", Estuar. Coast. Shelf Sci. 48, 701–723.

"The importance of these nurseries to reef fish population dynamics has not been quantified. Indeed, mangroves might be expected to have negligible influence on reef fish communities: juvenile fish can inhabit alternative habitats and fishpopulations may be regulated by other limiting factors such as larval supply or fishing6. Here we show that mangroves are unexpectedly important, serving as an intermediate nursery habitat that may increase the survivorship of young fish. Mangroves in the Caribbean strongly influence the community structure of fish on neighbouring coral reefs. In addition, the biomass of several commercially important species is more than doubled when adult habitat is connected to mangroves."^[5]

• Mumby PJ, Dahlgren CP, Harborne AR, Kappel CV, Micheli F, Brumbaugh DR, Holmes KE, Mendes JM, Broad K, Sanchirico JN, Buch K, Box S, Stoffle RW and Gill AB (2006) "Fishing, trophic cascades, and the process of grazing on coral reefs" Science, 311(5757):98-101.

Giant triton (snail) -> Crown-of-thorns starfish -> Hard coral

"One of the few predators of the crown-of-thorns starfish, the giant triton (Charonia tritonis) has evolved a tolerance to the starfish's toxins. Unfortunately, tritons can no longer keep starfish populations in check since they've been overharvested for their beautiful shells. With too few tritons on the reef, crown-of-thorns starfish populations can explode, jeopardizing the living coral that makes up reefs."^[6]

"Covered with long, venomous spikes, the crown-of-thorns starfish (Acanthaster planci) is a voracious feeder that can eat living corals because of a unique adaptation: a wax-digesting enzyme system. Populations of the starfish were once kept low by a few key predators, namely the giant triton. Since humans decimated giant triton populations, crown-of-thorns starfish outbreaks periodically kill vast expanses of hard coral."^[6]

"Hard corals have evolved to have large amounts of a wax (cetyl palmitate) in their tissues. Very few predators can digest the wax, which has allowed corals to flourish and produce massive reefs. Recently, epidemic populations of one predator -- the crown-of-thorns starfish -- have done extensive damage to many reef regions. Armies of grazing starfish leave a wake of destruction in their path, killing up to 95 percent of the hard corals in an area."^[6]

Tiger shark -> Green sea turtle

"Lurking around the edges of reefs during the day, tiger sharks (Galeocerdo cuvier) have evolved as highly aggressive "top" predators that grow at least 25 feet long. They detect prey using an array of finely tuned senses, including electrical current detection. Rows of razor-sharp teeth and powerful jaws allow them to crack though even the thick carapace (shell) of full-grown sea turtles."^[6]

"One common defense against predators is a protective covering, such as a shell. Another is to flee the predator. During its evolution, the green sea turtle (Chelonia mydas) sacrificed speed in favor of a thick, heavy shell (carapace). The carapace acts as armor, protecting the turtle's body from the sharp teeth of predators. But some, like the tiger shark, are powerful enough to bite right through the carapace and kill the turtle."^[6]

Sea slug -> Sea sponge

"Many sea sponges, like anemones, use toxins to repel would-be predators. Some species of sea slugs, however, such as Platydoris scabra, have evolved immunity against the toxins of specific sponge families (in this case, Microcionidae). This adaptation benefits the slugs in two ways. First, they don't have to compete with many other organisms for the sponges. The sea slugs can also concentrate the sponge toxins to foil their own predators -- at least until the slugs' predators also evolve immunity to the toxins."^[6]

"Sea sponges, such as those of the Microcionidae family, have escaped predation by all but a few species because they produce foul-tasting and sometimes toxic compounds. These compounds evolved as chemical weapons for use against other sponges, as well as against fouling organisms (creatures that grow on top of other creatures, thus decreasing their fitness) -- their defensive function was just a lucky side effect. But some predators, such as sea slugs, have evolved resistance to the toxins and even use those toxins against their own predators."^[6]

Bluestriped fangblenny (fish) -> Reef lizardfish

"Many large fish, including the reef lizardfish (Synodus variegatus), regularly visit the bluestreak cleaner wrasse to have skin, mouth, and gill parasites removed. The two fish benefit by the association; a third fish, however, has evolved to take advantage of them both. Using a devious disguise and copycat behaviors to attract larger fish, the fanged ambush predator, called a fangblenny, rips living tissue from surprised prey."^[6]

"In the world of predators and prey, the normal rule is that big creatures eat smaller creatures. But sometimes the tables are turned, as in the case of the bluestriped fangblenny (Plagiotremus rhinorhyncos), a small but sinister predatory fish. Evolved to perfectly mimic the bluestreak cleaner wrasse, the fangblenny falsely advertises cleaning services to larger fish, such as the reef lizardfish. Once the bigger fish moves in close, the fangblenny attacks and darts away with a mouthful of sushi."^[6]

Cone shell (snail) -> Blueband goby (fish)

"Coneshells (Conus spp.) are gastropod mollusks, closely related to the more familiar and harmless land snails. With beautiful, ornately designed shells, coneshells are highly sought-after by shell collectors. These gastropods have evolved as deadly predators, however; a single puncture from their venomous radula (modified tooth) can rapidly paralyze and even kill a human. Of course, coneshells evolved not to defend themselves against collectors, but to efficiently kill prey, such as the blueband goby."^[6]

"Gobies are the most diverse fish family on the reef, with more than 200 species described. With their generally small sizes and ability to adapt to a wide variety of specialized habitats, gobies have become the most diverse marine fish family in the world. This does not mean they are always successful at avoiding predators, though. For instance, the blueband goby (Valenciennia strigata) is eaten by a variety of predators, including the venomous coneshell."^[6]

Silver gull -> Black noddy

"Coming ashore only to breed (as do most true seabirds), black noddies (Anous minutus) form immense colonies of up to 100,000 nesting pairs on larger reef islands. Noisily chattering as they work, mating pairs build nests of guano-cemented leaves and grasses in fig trees. But even in the shelter of the trees, chicks and eggs are often stolen and eaten by marauding silver gulls."^[6]

"The common silver gull (Larus novaehollandiae), like most gulls, will eat just about anything it can get its heavy, hooked bill into. Often scavenging recently dead animals and even trash, silver gulls help keep shore areas clear of debris. But once the debris is gone, they turn to other easy pickings: eggs and chicks of other seabirds, such as the black noddy."^[6]

Pacific Reef Heron -> Fish fry

"Pacific Reef Herons , unlike true seabirds, live onshore year-round. While seabirds hunt far out beyond the reef, reef herons fish along the cay and reef flat. They have evolved to hunt during low tide, allowing them to wade the shallows. With excellent eyesight and marksman-like aim, they expertly spear fish fry, adult fish, and crustacean prey from beneath the water's surface."^[6]

"Silvery schools of many species of juvenile fish (called fish fry) find some refuge from the intense predation of outer reef zones by living near the shoreline. But they can't let down their guard completely. While feeding on benthic algae and floating microscopic communities of plants and animals, they are easily visible from above the water's surface and often fall prey to hunting reef herons."^[6]

"Humans have found many ways around the vicious game of biological competition. You didn't crawl out of the hospital nursery past hordes of hungry predators, and you probably didn't fight anyone for your breakfast this morning. But other species compete all their lives for limited resources of food, space, and mates. When resources are plentiful, competition weakens. But when resources are scarce, competition can become an all-out war for survival and reproduction. While competition seldom gets truly violent, the outcome often determines which of the competitors will get its genes into the next generation. The winners will pass on their genes -- and, thus, their winning traits -- to their offspring, while the losers' genes will disappear. Thus, each successive generation faces stiffer competition than the last, as individual competitors become better and better adapted ("fit") to their environments."^[7]

Ghost crab <-> Hermit crab

Bottlenose dolphin <-> Bigeye trevally (fish)

"The bottlenose dolphin (Tursiops truncatus) and other toothed whales are solitary predators who remotely detect prey by echolocation. Emitting a series of clicks and whistles, the dolphin then waits to analyze returning echoes. Echolocation is so precise that a dolphin can determine the size, direction, and distance of a school of prey fish, and even sizes of individual fish in the school. To feed, dolphins use a fast, surprise attack, and, unlike the hunting packs of trevallies, dolphins can successfully hunt alone."^[7]

"Bigeye trevallies (Caranx sexfasciatus) prey on schools of small fish using a very different approach than do bottlenose dolphins. These trevallies have evolved to cooperate with each other, much like wolves in a pack, to surround, corner, confuse, and finally kill their prey. A single trevally would have a very difficult time attacking a school of prey fish, with its hundreds of pairs of watchful eyes and ability to move as a unit to avoid predators, so each trevally benefits from participating in the hunting party."^[7]

Spanish dancer (slug) <-> Sea sponge

"Male Spanish dancers (Hexabranchus sanguineus) essentially enter dance competitions to win their mates. The judge is the desired female, who decides which writhing, scarlet red male wins the right to father her offspring. This process is an example of "sexual selection," in which a male "wows" a female into mating with him. Often, as in the case of Spanish dancers, the male risks his life to put on a winning show, since his mating behavior makes him more conspicuous to predators. Fortunately, Spanish dancers possess a potent toxin, which deters predators."^[7]

"Sea sponges and other sessile (anchored) organisms compete fiercely with each other for space using physical and chemical warfare. Over millions of years of turf wars, sponges that evolved anti-sponge toxins, like the Microcionidae, were often victorious over non-toxic varieties. Thus, most sponges living today produce potent toxins, which provide a secondary benefit of discouraging all but the most highly adapted predators, such as the sea slugs."^[7]

Bluestriped fangblenny (fish) <-> Bluestreak cleaner wrasse

"The bluestriped fangblenny (Plagiotremus rhinorhyncos) has evolved to look and act just like a bluestreak cleaner wrasse. Why? So it can take advantage of the bluestreak's symbiotic relationship with larger fish. The bluestreak gently nibbles away parasites from its customers, but the mimic blenny unveils fang-like teeth that quickly strip healthy flesh from unsuspecting victims."^[7]

"The bluestreak cleaner wrasse (Labroides dimidiatus) advertises its station by darting back and forth. Many fish regularly visit the station to have parasites removed by the bluestreak. Unfortunately, the bluestriped fangblenny has evolved to look and act just like a bluestreak. Not only do fangblennies compete with bluestreaks for customers, they also attack them and may make fish less trusting of true bluestreaks."^[7]

Cuttlefish <-> Cuttlefish

"Cuttlefish (Sepia spp.) are masters of disguise, changing appearance by opening and closing pores in their skin (called chromatophores) to reveal or hide underlying layers of different colors. Males competing for females put on their flashiest zebra-striped patterns, but the show isn't meant for the females at all. Instead, larger, dominant males seem to win breeding rights to females by intimidating their opponents with both size and more intense zebra patterns."^[7]

Ghost crab <-> Hermit crab

"As animal carcasses wash up on the beach and bake in the sun, they become storehouses of bacteria that easily spread diseases to living animals. Fortunately, stalk-eyed ghost crabs (Ocypode spp.), which live in burrows beneath the sand, relish dead animals and have evolved excellent chemical senses that enable them to quickly locate a newly arrived food source. They have much competition, though, including hermit crabs, which lay claim to carcasses still in the water."^[7]

"Hermit crabs (Dardanus megistos) are aquatic, near-shore scavengers that can grow to almost a foot across. Lugging a "borrowed" shell on their backs, they crawl across the sandy bottom searching for dead animals. Since their heavy shells prevent them from moving efficiently on land, stalk-eyed ghost crabs usually win the feast there. But underwater, carcasses swarm with hermit crabs, which quickly tear animals apart using their dexterous mouthparts."^[7]

"Free rides and win-win situations: Commensals and Mutualists Between predator-prey and competitive relationships, it may seem that organisms are alone in the world, fighting to survive and reproduce. But many organisms have evolved cooperative strategies for survival and reproduction. In these species "partnerships," at least one partner benefits, and neither is harmed. If only one partner benefits, and the other is not much affected, the relationship is called commensalism. Consider barnacles that attach themselves to whales. The whales aren't harmed, but the filter-feeding hitchhikers get ferried around the ocean and may find more food than if they were stuck in one place. If both partners feel the effects of the other, their relationship is called mutualism. In this case, each species tends to evolve adaptations to the other (that is, they coevolve) in order to maximize benefits and minimize losses caused by their close association."^[8]

Manta ray <-> Remora

"Among the largest living fishes, manta rays can reach 20 feet in width and weigh more than two tons. Like most marine behemoths, they are filter feeders. Using an unusual pair of "head flaps," they funnel tiny prey, such as small fish, crustaceans, and comb jellies, into their gaping mouths. Whatever morsels escape might be wasted, but are frequently caught and eaten by hitchhiking remoras."^[8]

Fast-swimming predators, like the manta ray, are messy eaters who leave behind a trail of food scraps. Remoras, or "suckerfish," have evolved a highly specialized body that allows them to exploit that resource. Fast swimmers, they easily catch up with a host and attach from below, using a powerful suction disc -- which evolved from an ordinary dorsal fin -- on top of their heads. The remoras' streamlined shape allows them to hitchhike without slowing down their hosts."^[8]

Hermatypic coral <-> Zooxanthellae

"It takes a lot of energy to secrete the calcium carbonate exoskeletons (hard outer structures) that make up coral reefs. Reef waters are typically very low in nutrients, so most coral animals can't filter out enough food to provide the extra energy they need. To make up for this deficiency, hermatypic corals shelter microscopic algae (zooxanthellae) within their tissues; in exchange, the algae supply the corals with carbohydrates so the corals have enough energy to build reefs."^[8]

"Zooxanthellae (pronounced "zoe-zan-thelly") are microscopic algae that live within the tissues of host animals, including hermatypic coral animals. Like all plants, zooxanthellae make their own food by a process called photosynthesis. Using solar energy absorbed by special pigments, they transform carbon dioxide into carbohydrates and oxygen. What they don't need themselves passes directly into the coral's gut cavity, providing the extra energy the coral needs to produce a calcium carbonate exoskeleton."^[8]

Calcareous algae <-> Branching coral

"Some multicellular algae on the reef produce calcium carbonate (limestone) skeletons very similar to those made by hard corals. These calcareous algae play a major role in barrier reef construction, acting as a sort of living mortar that holds together individual coral colonies. Growing between corals and wrapping around the bases of branching corals, calcareous algae protect the corals from erosion, especially in high-energy areas.

"Individual coral colonies, especially branching corals, can easily be toppled in high-energy reef zones, such as the reef front and rock rim. Waves can easily scour away sediments from a colony's base, uprooting it and pushing it along like tumbleweed. So how do branching corals ever get a solid foothold in such zones? Calcareous algae grow between corals and around their bases, preventing erosion and stabilizing the reef structure."^[8]

Clown anemonefish <-> Sea anemone

"Nestling among the venomous stinging tentacles of a sea anemone seems like a very bad survival strategy -- unless you and the anemone have some kind of an arrangement. Clown anemonefish (Amphiprion akindynos) and sea anemones have evolved just such a relationship. As juveniles, clownfish perform a ritual of "anemone rubbing." Initially protected from stings by a thick mucus coat, the clownfish incorporates anemone mucus into its own coat until the anemone no longer stings it, apparently recognizing the fish as part of itself. From then on, they defend each other, and clownfish have even been seen dragging food to their host anemone.

"Reef animals are masters of disguise, and sea anemones are no exception. Attached to the reef by a suction disc, tentacles swaying with the current, they are the animals perhaps most often mistaken as plants. The illusion is further reinforced by the presence of two or more commensal clownfish among the tentacles. But the clownfish and anemone are a predatory team, working side by side and sharing food. In addition, the clownfish fight off intruders, such as anemone-eating butterflyfish, and the stinging cells (nematocysts) of the anemone deter potential clownfish predators."^[8]

Sponge crab <-> Sea sponge

"Sponge crabs (Dromiidae family) avoid predators by carrying a disguise with them at all times. Their posterior legs are modified for grasping, and the crabs use them to carry live Halichondria sponges on their backs. Since the sponges are toxic to most potential predators, the undercover crab doesn't have to worry about being attacked and can concentrate on more important things, like finding food."^[8]

"Many sea sponges have evolved chemical weaponry for use against other sessile organisms in the never-ending battle for space on the reef. Since the compounds tend to be distasteful and often toxic to predators, the sponges avoid most predation. Sponge crabs exploit this defense by carrying live sea sponges on their backs. And the sponges may benefit, too: By living atop a crab, they no longer have to battle for space."^[8]

Giant clam <-> Zooxanthellae

"Myths about divers being caught and eaten by giant clams (Tridacna gigas) still abound. The clams, though immense (up to three feet across and weighing more than 200 pounds), are not man-eaters. In fact, they are filter feeders that strain tiny food particles from the water. They get whatever additional nutrition they need from symbiotic algae, such as zooxanthellae, similar to those found in reef-building corals."^[8]

"Zooxanthellae are microscopic algae that live within the tissues of a variety of host animals, including giant clams. Like all plants, zooxanthellae use energy from sunlight to make their own food by a process called photosynthesis. Excess food leaks out of the algae and into the filter-feeding clam, which relies on the algae's extra energy to survive. Because zooxanthellae make food most efficiently in fairly shallow, well-lit waters, giant clams are most abundant there too."^[8]

Upside-down jellyfish <-> Zooxanthellae

"Jellyfish are soft-bodied, free-swimming animals closely related to the corals. Most jellyfish are predators, using the tentacles that drape from their floating bell to ensnare and paralyze prey. A few species of so-called upside-down jellyfish (Casseiopea medusae), however, have literally "flipped their lids." They float upside-down, and their tentacles are blanketed with symbiotic zooxanthellae that use solar energy to make food for the jellyfish.

"Zooxanthellae are microscopic algae that live within the tissues of host animals, including hermatypic corals, giant clams, and upside-down jellyfish. The jellies may be the best hosts of all because they can swim to a depth where the zooxanthellae have optimal sunlight levels. The tiny plants cover the tentacles of the jellies, making food by photosynthesis and releasing whatever they don't need right into the jellyfish's tissues."^[8]

Tern <-> Ghost crab

"Every living organism eventually dies, whether killed by a predator, a disease, or just "old age." Leftover pieces of prey and whole carcasses comprise a valuable source of food. Not surprisingly, a large group of organisms, called detritovores, have evolved in a way that lets them take advantage of this resource in every environment. For example, stalk-eyed ghost crabs eat carcasses, such as dead terns, that wash up on cay beaches. In turn, living terns (Sterna spp.) benefit by being spared carrion-associated diseases."^[8]

"Ghost crabs (Ocypode spp.) perform a great cleanup service as they get a meal. Quickly pinpointing the location of newly arrived carcasses, masses of crabs share in the feast while the carcass is still fresh. Living terns may even benefit from the crabs' work by being spared exposure to disease-causing bacteria that would otherwise build up on their rotting kin."^[8]

Giant triton <-> Hermit crab

"When a giant triton dies, its tissues will likely be consumed by a group of detritovores, organisms evolved to eat dead and decaying organic matter. But the marvelous, and often enormous (up to 20 inches across), calcareous shell made by the living triton cannot be eaten. Instead, it will quickly be claimed by a hermit crab, which cannot make a shell of its own for protection."^[8]

"Unlike other crabs, hermit crabs (such as Dardanus megistos) are unable to make a thick, protective shell (carapace) for its hind-end. While the head and legs are well protected from predators, the vulnerable back-end must be tucked inside a shell scavenged from the reef floor after its original owner dies. Each time the hermit crab outgrows its shell, it must find a larger one and then move in quickly to avoid being eaten."^[8]

"Sometimes, hermit crabs carry other organisms, such as sea anemones, on their shells. These hitchhikers help camouflage the crabs. When a hermit crab changes shells, often the anemone will transfer to the new shell and continue along with its crab friend. Dardanus crabs often place sea anemones on their shells, which works well for both animals. The hermit crab gets a little extra protection from other sea creatures, because sea anemones are poisonous, which makes other creatures wary of them. The anemones get leftover food from the crab and a free ride. In places where discarded shells are hard to come by, hermit crabs may cover themselves with pieces of bamboo or coconut shell. Others hide among coral reefs."^[9]

---

One of the greatest barriers to achieving sustainability on any major scale right now is that corporations (and individuals) are able to treat the environment as an externality. Thus ecological costs are not calculated as part of true costs.

Natural resources have always been economically significant; this includes ecosystem services, such as the ability of the oceans to provide food and absorb waste, which have in the past tended to be regarded as unlimited or free.^[10]

The economic importance of nature is indicated by the use of the expression ecosystem services to highlight the market relevance of an increasingly scarce natural world that can no longer be regarded as both unlimited and free.^[11] In general as a commodity or service becomes more scarce the price increases and this acts as a restraint that encourages frugality, technical innovation and alternative products. However, this only applies when the product or service falls within the market system.^[12] As ecosystem services are generally treated as economic externalities they are unpriced and therefore overused and degraded, a situation sometimes referred to as the Tragedy of the Commons.^[11]

One approach to this dilemma has been the attempt to "internalise" these "externalities" by using market strategies like ecotaxes and incentives, tradeable permits for carbon, water and nitrogen use etc., and the encouragement of payment for ecosystem services.

Treating the environment as an externality may generate short-term profit at the expense of sustainability.^[13] Sustainable business practices, on the other hand, integrate ecological concerns with social and economic ones (i.e., the triple bottom line).^[14] Growth that depletes ecosystem services is sometimes termed "uneconomic growth" as it leads to a decline in quality of life.^[15][16]

Rather than treating the environment as an externality, by focussing on the triple bottom line, sustainable business practices attempt to integrate ecological concerns with social and economic ones. This approach views sustainability as a business opportunity. Waste in an industrial process is often a sign that inputs are being used inefficiently; waste itself can be seen as an "economic resource in the wrong place". The benefits of waste reduction include savings from disposal costs, fewer environmental penalties, and reduced liability insurance, in addition to increased market share due to an improved public image.^[17] Energy efficiency can also increase profit margins through reducing costs. The concept of sustainability as a business opportunity has led to the formation of organizations such as the Society for Organizational Learning's Sustainability Consortium, oriented towards large corporations, as well as regional groups such as Entrepreneurs for Sustainability in the Greater Cleveland area which are oriented towards small and medium sized enterprises.^[18] The idea of sustainability as a driver of job creation was pushed in the 2008 presidential election by Barack Obama through the rhetoric of Green-collar jobs.^[19]

Economic opportunities are sometimes in conflict with uneconomic growth. In human development theory, welfare economics (the economics of social welfare), and some forms of ecological economics, is economic growth that reflects or creates a decline in the quality of life. The concept is attributed to the economist Herman Daly, though other theorists can also be credited for the incipient idea.^[20][21] Note that economic degrowth is different from uneconomic growth (or uneconomic degrowth), it is meant as a reduction of the size of the economy that would bring well-being and sustainability, see http://events.it-sudparis.eu/degrowthconference/en/.

"Practices destructive to coral reefs can be the result of externalities – the people who cause the damage benefit from unsustainable economic activities, but the costs are borne by others who depend in some way or other on coral reefs.

"Economists argue that this is often due to the absence of a well-functioning market for environmental goods and services. Hodgson and Dixon (1988) describe an externality situation in which logging causes sedimentation that results in reef degradation (affecting tourism) and fishery losses. For the logging company, these tourism and fishery losses are not part of their profit calculation. In the absence of government policy and/or public outcry, logging would continue even if the external costs to society were much higher than the net profits of the logging industry, as was the case in the example of Hodgson and Dixon."

"This example indicates two things. First, it shows the importance of a stakeholder analysis of who is gaining and who is losing from a situation and the potential for a possible intervention; and, second, it shows the importance of obtaining economic values for the various reef goods and services, e.g. a fishery value and a coastal protection value. Some of these goods and services involve concrete marketable products, such as shellfish, for which the value can be determined based on the demand, supply, price and costs. Other services depend on the possible future uses of yet unknown biodiversity on reefs for which, sometimes, markets can be created. The values of all these goods and services together form the total economic value (TEV) of reef ecosystems (e.g. Spurgeon 1992). This TEV can be calculated for a specific area or for other uses (e.g. preservation area, tourism area, multiple use area, etc.). Economic valuation can also be used to calculate the economic losses due to destruction of reef functions, as in blast fishing (Pet-Soede et al. 1999), coral mining (Berg et al. 1998) or bleaching (Westmacott et al. 2000c). The three case studies in this paper discuss each of these points. These case studies are briefly summarized here. "

Sustainability in these programs is generally defined to include economic, environmental, and social sustainability, collectively known as the Triple Bottom Line. For each of these domains, sustainability means that it will be possible to continue through the foreseeable future, at least, without major breakdowns, such as

• Economic: running out of oil or other natural resources and having nothing to replace them on the scale required
• Environmental: loss of habitat, species, and whole ecologies; global warming
• Social: overpopulation beyond the carrying capacity of the Earth; consequences of eliminating poverty within the current economic model; ensuring equity and social stability in development.

The environmental and social justice movements are sources for many of the issues, arguments, and research on sustainability, but the idea has firm roots in Classical Economics.

• Externalities: Economically significant effects of manufacturing and trade on those who are not part of the industry or market in question. The classic example of a negative externality is pollution, while the largest current issue is Global Warming. The literature has identified many others, and many positive externalities, and has proposed many controversial measures to improve the balance.
• Natural resources: Conventional accounting, including national accounts, treats extraction of finite natural resources as income, priced at the cost of extraction, and not as depletion of non-renewable Natural Capital. The resources of Nature come to us for free. They are of infinite value from the point of view of preserving and sustaining life, but may not be subject to trading in a market, as in the case of air for breathing, for agriculture, or for burning fuels.
• The problem of value: Conventional economics can describe the process of setting prices in a marketplace through the interaction of supply and demand, but cannot adequately explain value. (Though not for lack of trying. See Labor Theory of Value and Util for examples.) The most economists generally agree on is that an individual purchaser in a Free Market will only buy something worth more to that individual than the price, and that the seller values the goods less than the price, so that both sides come out ahead.
• Participation: The so-called Free Market is not free to those who have no access to it.

One of the themes of sustainable MBA education is the extent to which environmental and social sustainability can be achieved at a profit, a question by no means answered fully.

---

Reference sites

marine photographers

IUCN status is here. If you search for the species' name (scientific name is generally best) the species will show up, if it has been rated. Most mammals, birds and amphibians have been rated, but in remaining groups (notably fish, invertebrates and most groups of plants) a large percentage have not. Reptiles and a few groups of plants are more or less in between, but they're getting there. For a few species wikipedia use the Endangered Species Act instead, but then the status system (in the taxobox) is ESA rather than IUCN (under that system there are also different categories, e.g. Endangerd is just "E" rather than the "EN" used in IUCN).

http://www.associatedcontent.com/article/30877/history_of_koi_fish.html?cat=53 History of Koi Fish (blacklisted)

• Traditional fishing boat at Lang Co Beach, between

  Hoi An

  and

  Hue

  ,

  Vietnam

• New Zealand bluff oysters ‎

• New Zealand green mussels ‎

• Vietnamese fishing coracles 03

• Vietnamese fishing boats 03

• Saint-Martin de Ré ‎

• Thai fishing boat 03

• Vietnamese fishing boat 04

• Polish fishing boat 02

• Mexican fishing boat

• Buoys on a fishing boat ‎

• African fishing boats 02

• Hoi An Fish Market, Vietnam)

• Fishing boats in New Zealand ‎

• Charter fishing boat in Hawaii

• Polish fishing boat

• Haitian fishing boat

• Fishing boats at Cape Verde

• Canadian fishing boat

• Brazillian fishing boat

• Fishing boat in the Canary Islands

• Vietnamese coracle fishing boat

• Irish fishing boat 02

• Irish fishing boat

• Traditional Maltese fishing boat

• Fishing boats in Brittany ‎

• Maltese fishing boats 02

• Maltese fishing boats

• Catching a big pike

• Vietnamese fishing coracles 02

• Ecuadorian fishing boat

• New Zealand fishing boat

• Shetland fishing boats

• Vietnamese fIshing coracle

• Caribbean fishing boats

• Indonesian fishing boats 03

• Filipino fishing boat

• Malaysian fishing boats

• Fishing boats in Jersey

• African fishing boats ‎

"Atlantic menhaden help maintain water quality by feeding on plankton and decaying plants. [They] filter a volume of water equal to the entire bay in less than one day.

Menhaden are filter feeders vital to the health of our Bays and near shore waters….. they filter up to four gallons a minute. This process holds in check red and brown tide as well as other algal blooms".^[22]

"But one company, Omega protein …. is annually catching billions of menhaden and converting them into cheap industrial commodities, such as pet food, hog feed, and oils used in paints, linoleum, and lipstick. Omega could wipe out this very important fish in a very short period of time leaving no natural element to deal with algal blooms.

Menhaden reduction is still practiced, mostly by the essentially monopolistic firm Omega Protein. It continues to take menhaden out, not just for fertilizer these days, but also for food pellets for chicken and farm-raised fish (you do eat menhaden, just not directly) and (as the name implies) for trendy fish oils."^[23]

(doi:10.1146/annurev.environ.33.020807.143204) First published online as a Review in Advance on August 1, 2008

predator birds

Red-breasted merganser

It helps predators to fish their prey

"The more prey, the more predators, says a time-worn ecological theory. However, this is not necessarily true. When there are few prey, the remaining prey grow more rapidly. This, in turn, can lead to more sexually mature individuals, which leads to more small prey, which the predator fish prefer. Paradoxically, a predator fish can therefore increase the amount of small prey fish by eating them. If there aren’t enough predatory fish, owing to increased harvesting, for instance, the reverse situation ensues. The number of prey that the predators live on will decline."

^[24][25]

Heating eyes to track prey

"Large and powerful predators such as swordfishes, tunas, and many sharks are unique among fishes in that they possess physiological mechanisms that warm their eyes. A new investigation reported this week sheds important light on the purpose of warming the eyes and the advantage that "warm eyes" confer on ocean predators."^[26]

Offshore predator fish^[27]

Predator fish help coral reefs recover^[28]

State of predator fish in the Great Lakes^[29]

• Burt, JR; Hardy,KJ and Whittle, M (editors) Pelagic Fish: The Resource and its Exploitation.
• Freon, Pierre and Misund, Ole Arve (1998) Dynamics of Pelagic Fish Distribution and Behaviour. Wiley-Blackwell. ISBN-13 978-0852382417

• Carp

• American gizzard shad

• Quillback

• Minnow

• Northern pike

• European perch

• Chinook salmon

• Brook trout

• Brown trout

Radio presentation: "Sixty per cent of the world's tuna comes from the Pacific. The fishery is worth over $2 billion to outside nations who fish in the region and $400 million to the nations of the Pacific. But as demand increases, there is growing concern that the relentless pressure on tuna stocks is putting them in substantial danger. Philippa Tolley travels to Busan in South Korea, where those involved in the industry are gathering to discuss the way ahead. The agenda includes one proposal to reduce the catch of some tuna species by 30 per cent."

"Are we killing off world fisheries?

Canada knows this situation very well, after its five hundred year old cod fishery collapsed in 1990 - and hasn't come back. Is that an isolated incident?

To find out, the Paulian researchers gathered catch data collected by the United Nations Food and Agriculture Organization, the FAO. Along with other scientists, they soon realized that while specific FAO information was very valuable, the total catches being reported were larger than life. Pauly says that China has been exaggerating fish catch reports, as they exaggerate wheat harvests, and other production statistics, to reflect the success of the State. The FAO said the overall world catch was going up. Dr. Pauly, and a chorus of independent fisheries scientists, said the global ocean harvest is actually declining.

The catch is dropping despite bigger, faster boats going much further, burning more fuel that ever before. Even satellite and sonar gear cannot increase the catch. Europe has exhausted many species in the North Sea, and must now go down to the coast of Africa to feed the European diet of fish, including the mandatory Friday seafood meal sanctioned by the Church."^[30]

"Fisheries have rarely been 'sustainable'. Rather, fishing has induced serial depletions, long masked by improved technology, geographic expansion and exploitation of previously spurned species lower in the food web. With global catches declining since the late 1980s, continuation of present trends will lead to supply shortfall, for which aquaculture cannot be expected to compensate, and may well exacerbate. Reducing fishing capacity to appropriate levels will require strong reductions of subsidies. Zoning the oceans into unfished marine reserves and areas with limited levels of fishing effort would allow sustainable fisheries, based on resources embedded in functional, diverse ecosystems."^[31]

To do: Add section on personal responsibility (?) to overfishing

The following refs are from http://www.seabeforeus.pwias.ubc.ca/details.php:

• Ainsworth, C. and Pitcher, T.J. (2008) Back to the Future in Northern British Columbia: Evaluating Historic Marine Ecosystems and Optimal Restorable Biomass as Restoration Goals for the Future. Pages 317-329 in Nielsen, J.L. et al. (eds) Reconciling fisheries with conservation. American Fisheries Society, Symposium 49, Bethesda, Maryland, USA, 1946 pp.
• Ainsworth, C.H., Pitcher, T.J. and Rotinsulu, C. (2008) Evidence of fishery depletions and shifting cognitive baselines in Eastern Indonesia. Biological Conservation, 141(3): 848-859.
• Ainsworth, C.H., Pitcher, T.J., Heymans, J.J. and Vasconcellos, M. (2008) Historical Reconstruction of the Marine Ecosystem of Northern British Columbia from Pre-European Contact to the Present. Ecological Modeling 216: 354-368.
• Bolster, W.J. and Alexander, K.E. (2008) Using Historic Records to Determine the Abundance of Cod on the Nova Scotian Shelf, 1852-1859: An Interdisciplinary Approach to the Environmental History of the Northwest Atlantic. In Jackson, J.B.C., Sala, E. and. Alexander, K.E (eds) Marine Biodiversity: Using the Past to Inform the Future. University of Chicago Press.
• Costanza, R., Graumlich, L., Steffen, W. et al. (2007) Sustainability or collapse: what can we learn from integrating the history of humans and the rest of nature? Ambio: 36: 522-527.
• Dulvy, N.K., Sadovy, Y., Reynolds, J.D. (2003) Extinction vulnerability in marine populations. Fish and Fisheries 4: 25-64.
• Garcia, S.M. and Cochrane, K.L. (2005) Ecosystem approach to fisheries: a review of implementation guidelines. ICES Journal of Marine Science 62: 311-318.
• Guénette, S., Heymans, S.J.J., Christensen, V. and Trites, A.W. (2006) Ecosystem models show combined effects of fishing, predation, competition, and ocean productivity on Steller sea lions (Eumetopias jubatus) in Alaska. Canadian Journal of Fisheries and Aquatic Sciences 63: 2495-2517.
• Lotze, H.K., Lenihan, H.S., Bourque, B.J. et al. (2006) Depletion, Degradation, and Recovery Potential of Estuaries and Coastal Seas. Science 312: 1806-1809.
• Lotze, H,K,, Reise, K,, Worm, B. et al. (2005) Human transformations of the Wadden Sea ecosystem through time: a synthesis. Helgoland Marine Research 59: 84-95.
• Lozano-Montes, H., Pitcher, T.J. and Haggan, N. (2008) Shifting environmental and cognitive baselines in the upper Gulf of California (Mexico): Local Fisher’s Knowledge reveals a slow- motion disaster. Frontiers in Ecology and the Environment 6(2): 75-80.
• Monte-Luna, P., Lluch-Belda, D., Serviere-Zaragoza, E., et al. (2007) Marine extinctions revisited. Fish and Fisheries 8: 107-122.
• Pauly, D. (1995) Anecdotes and the shifting baseline syndrome of fisheries. Trends in Ecology and Evolution 10: 430.
• Pauly, D., Pitcher, T.J. and Preikshot, D. (eds) (1998) Back to the Future: Reconstructing the Strait of Georgia Ecosystem. Fisheries Centre Research Reports 6(5): 99pp.

Pitcher, T.J. (1998) "Back to the Future": a Novel Methodology and Policy Goal in Fisheries. Pages 4–7 in Pauly, D., Pitcher, T.J. and Preikshot, D. (eds) Back to the Future: Reconstructing the Strait of Georgia Ecosystem. Fisheries Centre Research Reports 6(5): 99pp.

• Pitcher, T.J. and Ainsworth, C. (2008) Back to the Future: A Candidate Ecosystem-Based Solution to the Fisheries Problem. Pages 365-383 in Nielsen, J.L., et al. (eds) Reconciling fisheries with conservation. American Fisheries Society, Symposium 49, Bethesda, Maryland, USA, 1946 pp.
• Pitcher, T.J., Kalikoski, D., Short, K., Varkey, D. and Pramod, G. (2008) An evaluation of progress in implementing ecosystem-based management of fisheries in 33 countries. Marine Policy doi:10.1016/j.marpol.2008.06.002.
• Robinson, J. (2008) Being Undisciplined: Transgressions and Intersections in Academia and Beyond. 28pp.
• Robinson, J. and Tansey, J. (2006) Co-production, Emergent Properties and Strong Interactive Social Research: The Georgia Basin Futures Project. Science and Public Policy 33(2): 151-160.
• Smith, A.D.M., Fulton, E.J., Hobday, A.J., Smith, D.C., and Shoulder, P. (2007) Scientific tools to support the practical implementation of ecosystem-based fisheries management. ICES Journal of Marine Science 64:
• Swart, R., Raskin, P., Robinson, J., Kates, R. and Clark, W.C. (2002) Critical Challenges for Sustainability. Science. Science 297: 1994-1995.
• Tesfamichael, D. and Pitcher, T.J. (2006) Multidisciplinary Evaluation Of The Sustainability Of Red Sea Fisheries Using Rapfish. Fisheries Research 78: 227-235.
• Turvey, S.T and Risley, C.L. (2006) Modelling the extinction of Steller’s sea cow. Biology Letters 2: 94–97.

Tim Adams

NOAO

From coast: Fisheries have lost much of their capacity to produce fish due to habitat degradation, and overfishing. Overharvesting, trawling, bycatch and climate change are among some of the major pressures on fisheries. Since the growth of the global fishing enterprise since the 1950’s, intensive fishing has gone from a few concentrated areas to encompass nearly all fisheries. Not only is over fishing a problem but the technology involved creates even greater destruction. Trawling, or bottom dragging, is used for catching shrimp and other bottom dwelling species. This scraping of the ocean floor is devastating to coral, sponges and other long-lived species that do not recover quickly. This destruction alters the functioning of the ecosystem and can permanently alter species composition and biodiversity. Bycatch is the result of capturing unintended species in the course of fishing. Of this unintended catch most is discarded back into the ocean and dies from injuries or exposure. Bycatch represents approximately ¼ of all marine catch. In the case of shrimp capture, the amount of bycatch is five times larger than the amount of shrimp caught.

behaviour

A fish is a cold-blooded, backboned, aquatic animal that lives in every region of the world. Fish are harvested for their highly nutritious meat and for the oil that is extracted and used as a food product or as an ingredient for a wide variety of commercially prepared products. There are numerous fresh water and salt-water fish species that are harvested throughout the world. Some of these species are shown below.

Fish live in water and breathe with gills. All fish have a backbone. All fish are cold-blooded, which means their internal body temperature changes as the surrounding temperature changes. Fish are very diverse.

1 Fish live and breathe in water. They use their gills to breathe, have fins and a streamlined body suitable for swimming, and have scales for protection. Fish are vertebrates - animals with a backbone. However, they are not the only animals with a backbone. Mammals (such as monkeys, horses, cats), reptiles (such as lizards, snakes), amphibians (such as frogs and toads), and birds also have a backbone, and they are all vertebrates.

2 There are over 25,000 different types of fish in the world - a count more than the combined total of mammals, reptiles, amphibians, and birds! Fish can be found in almost every type of underwater environment. For example, the Antarctic icefish can survive in water below the freezing point (32 degrees Fahrenheit) because their blood contains special anti-freeze chemicals to prevent their body from freezing. Sharks, salmons, electric eels, and seahorses are other examples of fish.

Fish can be divided into three groups: jawless fish, cartilaginous (pronounced "KAR-ti-LAJ-i-nus") fish, and bony fish. Both cartilaginous and bony fish have jaws.

This category includes the following types of fish:

plaice 
Dover sole 
lemon sole 
turbot 
brill 
halibut. 

White flat fish have white flesh and are flat. Turbot, brill and halibut are very large flat fish, but are readily available from suppliers and popular in many fine restaurants. The cuts of flat fish are different to those of round fish. Figure 9.1 a Dover sole, b brill, c halibut, d turbot, e lemon sole,

The following types of white round fish are included at NVQ Level 2:

cod 
haddock 
hake 
huss 
whiting 
monkfish. 

These fish are round and are relatively common in UK coastal waters. Like flat fish, their flesh is white but the cuts are different.

This category includes the following fish:

salmon 
trout 
mackerel 
tuna 
herring 
sardines 
anchovies. 

All oily fish are round and the flesh is darker than that of white fish. White fish contain oil, but only in their livers, whereas oily fish have oil throughout their bodies.

Crustaceans

prawns 
shrimp 
squid 
crab 
lobster 
crayfish

Fish can be divided into three groups: jawless fish, cartilaginous (pronounced "KAR-ti-LAJ-i-nus") fish, and bony fish. Both cartilaginous and bony fish have jaws.

• Freshwater Fish: Catfish, Grayling, Pickerel, pike, Rainbow Trout, sunfish, Tilapia (also saltwater), trout, Walleye Pike, whitefish, Zander
• Migratory Fish: Eel, salmon (anadromous), shad (anadromous), smelt(anadromous), Striped Bass, Sturgeon (anadromous)
• Saltwater Fish
• Types of fish

Fisheries in New Zealand

In New Zealand, we have different types of fisheries. We have:

   * inshore fisheries 
   * deep-water and middle-depths fisheries 
   * fisheries for highly migratory species 
   * freshwater fisheries.

Inshore fisheries are found on our continental shelf – up to depths of 200 metres. These fisheries include paua, rock lobster, snapper, tarakihi, kahawai, and even some types of seaweed. Map showing New Zealand's EEZ and Territorial Sea. Deep-water and middle-depths fisheries are generally found in deeper waters – but still within our Exclusive Economic Zone (EEZ). An EEZ is an area of sea that one country has the special right to explore and take marine resources from. Our EEZ extends 200 nautical miles, (which is 370 kilometres) out to sea from the coastline of New Zealand. The deep-water fisheries in our EEZ include six of our 10 most important commercial species of fish – squid, hoki, orange roughy, ling, hake, and jack mackerel.

Highly migratory species are the types of fish that travel great distances – through the EEZs of different countries and into the seas that don’t belong to anyone – the high seas. These fisheries include different kinds of tuna, marlin, swordfish, and some types of shark, including the blue shark and the mako shark.

Freshwater fisheries are found in rivers and lakes. The freshwater fisheries currently managed by the Ministry of Fisheries (MFish) include eel, catfish, different kinds of carp, freshwater shrimp, and even goldfish! Sharing our fisheries

All the fisheries in New Zealand are important to different types of fishers, including commercial fishers, Māori customary fishers, and recreational fishers.

When a fishery is important to more than one type of fisher, we call it a shared fishery. Most shared fisheries are found inshore. They are fisheries like snapper, blue cod, kahawai, rock lobster, and paua. But some offshore fisheries, such as swordfish, and freshwater fisheries, such as the eel fishery, are also shared fisheries.

MFish works with all those groups of fishers who are involved in a shared fishery. The goal is to try to make sure that everyone can catch enough fish for their needs while still leaving fish for the future. This can be a difficult task, as each group has different but equally important needs.

^[32]

Different groups, such as oceanographers, marine biologists, aquatic ecologists, fisheries scientists and navies, find it convenient to divide the sea into various coastal and oceanic zones. However the different groups can view these zones in somewhat different ways.

• Oceanographers may look at the zones from the point of view of their physical attributes including temperature, salinity, mixing, chemistry movements and interactions, waves, internal waves, tides and currents.
• marine biologists may think of the zones as
• aquatic ecologists may view the zones as ecological habitats.
• fisheries scientists might view the zones in the way they relate to particular fisheries..
• Navies may look at the littoral zone from the point of view of littoral combat and at thermoclines from the point of view of masking submarines from sonar.

Because of these diverse ways of looking at the ocean, it is not surprising that different disciplines and interest groups can be more interested in certain zones and less interested in others, and can define the same ocean zones and regions in slightly different ways.

Oceans are divided into numerous regions depending on the physical and biological conditions The pelagic zone includes all open ocean regions, and can be subdivided into further regions categorized by light abundance or depth.

The photic zone is defined as the water from the surface down to the point where the sunlight intensity has dropped to one percent of that at the surface. How far down this is depends on how clear the water is. In very murky waters, such as eutrophic lakes, light might penetrate only a few centimetres. In the open ocean the zone can extends to 200 metres or more. The depth of the photic zone is affected by seasonal turbidity.

This is the region where there is sufficient sunlight for photosynthesis to occur. It contains the largest biodiversity in the ocean. Since plants can only survive with photosynthesis, life lower than the photic zone must rely on material floating down from above (marine snow) or find another primary source, such as hydrothermal vents.

The pelagic part of the photic zone is known as the epipelagic.

The photic zone is the depth of the water in a lake or ocean, that is exposed to sufficient sunlight for photosynthesis to occur.

The aphotic zone is the water in an ocean or lake that is below the photic zone, that is, it is the depths beyond where the light intensity is leaa than one percent at the surface. Little ot no photosynthesis occurs here, and as you go deeper, bioluminescence is the only light normally found in this zone.

Unusual and unique creatures dwell in this expanse of pitch black water, such as the gulper eel, the giant squid, the anglerfish, and the vampire squid.

The aphotic zone is divided into two parts- the bathyal zone and the abyssal zone. The bathyal zone extends from 200 meters^{[citation needed]} to 2000 meters. The abyssal zone extends from 2000 meters to the bottom. Creatures in this area must be able to live in complete darkness.

The pelagic part of the aphotic zone can be further divided into regions that succeed each other vertically. The mesopelagic is the uppermost region, with its lowermost boundary at a thermocline of 12 °C, which, in the tropics generally lies between 700 and 1,000 m. After that is the bathypelagic lying between 10 °C and 4 °C, or between 700 or 1,000 m and 2,000 or 4,000 m. Lying along the top of the abyssal plain is the abyssalpelagic, whose lower boundary lies at about 6,000 m. The final zone falls into the oceanic trenches, and is known as the hadalpelagic. This lies between 6,000 m and 10,000 m and is the deepest oceanic zone.

Along with pelagic aphotics zones there are also benthic aphotic zones, these correspond to the three deepest zones. The bathyal zone covers the continental slope and the rise down to about 4,000 m. The abyssal zone covers the abyssal plains between 4,000 and 6,000 m. Lastly, the hadal zone corresponds to the hadalpelagic zone which is found in the oceanic trenches. The pelagic zone can also be split into two subregions, the neritic zone and the oceanic zone. The neritic encompasses the water mass directly above the continental shelves, while the oceanic zone includes all the completely open water.

In contrast, the littoral zone covers the region between low and high tide and represents the transitional area between marine and terrestrial conditions. It is also known as the intertidal zone because it is the area where tide level affects the conditions of the region.

Depth and layers

Depending on how deep the sea is, there can be up to five vertical layers in the ocean. From the top down, they are:

Organisms in the deep sea are almost entirely reliant upon sinking living and dead organic matter which falls at approximately 100 metres per day.^[33] In addition to this, only about 1-3% of the production from the surface reaches the sea bed mostly in the form of marine snow - as mentioned above. Larger food falls, such as whale carcasses, also occur and studies have shown that these may happen more often than currently believed. There are lots of scavengers that feed primarily or entirely upon large food falls and the distance between whale carcasses is estimated to only be 8 kilometres.^[34] In addition, there are a number of filter feeders that feed upon organic particles using tentacles, such as Freyella elegans.^[35]

In contrast, deep water benthic species, elopomorph ( halosaurs, spiny eels and cutthroat eels), and Paracanthopterygians (eg brotulids, cusk eels, cods, and grenadiers), are in orders that include many related shallow water fishes. "^[36]

Pelagic fish are fish that live in the pelagic zone.

"Pelagic fish live in the water column, which distinguishes them from groundfish. They feed primarily in the surface layers or a short distance below the surface, and frequently travel in large schools, turning and manoevring in close formation.

"Fish that swim near the surface, compared with demersal fish, which live on the sea bottom. Pelagic fish are mostly of the oily type such as herring, mackerel, and pilchard, containing up to 20% oil.

• Fish that live alone or in schools at or near the surface
• Surface feeding or free swimming fish.
• Fish that are normally caught at or near the sea surface or in the water column.

"schools of pelagic fish such as mackerels, kahawai, trevally, skipjack tuna, pilchards, and anchovies

"Small pelagic fish species such as herring, mackerel, horse mackerel, sardinella, blue whiting, sardine and silversmelt, swim together in shoals and often migrate over large distances in the sea

"The “pelagic zone” refers to the open waters of the ocean. Fish that live in pelagic zones are typically mobile and migratory species that are not closely associated with permanent structures such as coral reefs. This behaviour makes pelagic fish difficult to study and understand because it is often impossible to observe them using Scuba gear typically employed by marine biologists. Therefore, it is useful to combine a variety of methods, including the vast knowledge of experienced fishermen, to learn about these important oceanic fish".^[37]

"Some of the largest and most commercially important species are pelagic fishes, including billfish, tunas, dorado, and many sharks. Most of the favorite sport fish in the Gulf of California are pelagic fishes, including billfish, tuna, jacks and dolphinfish".^[37]

• McLintock, A H (Ed) Te Ara - The Encyclopaedia of New Zealand:

Fish, Marine Updated 18-Sep-2007

• Carl Walrond. Encyclopedia of New Zealand: Oceanic fish Updated 21-Sep-2007

note no agriculture or fisheries and fishing.

Copy of google answer...^[38]

"What percentage does the human race make up in compare to animal life, vegatation and insect on earth

Answer Thanks for an interesting question.

We humans like to think of ourselves as the powers-that-be on planet Earth, and perhpas we're justified in that.

But in terms of biomass, we're just small potatoes. In fact, although potatoes don't necessarily outweigh us, the total mass of agricultural crops amounts to about 9-10 times more weight than the biomass of humans.

There is twice the biomass of krill as that of humans. Bacteria in the ocean -- at least 150 times the biomass of we mere human beings.

Overall the combined weight of biological material -- animals, plants, insects, crops, bacteria, and so on -- has been estimated in one source at about 75 billion tons. Of this:

--humans comprise about 250 million tons (0.33%)

--krill, about 500 million tons (0.67%)

--farm animals, 700 million tons (almost 1%)

--crops, 2 billion tons (2.7%)

Although these numbers are intriguing, they should be taken with a very large grain of salt. Although there is a pretty good inventory of the world's number of people and crops -- hence reasonable estimates of their total biomass -- this is not the case with most other biological materials. Hence, the numbers are only educated guesses (and in some cases, not-so-educated guesses).

Other problems arise with the way people 'measure' biomass -- sometime total organism weight is used, sometimes only dry weight, which ignores the part of the organism made up of water. As you can imagine, that would make for some wildly divergent numbers.

Smaller problems arise with imprecise use of units -- sites are not always clear when they are using English 'tons' or metric 'tonnes', although the difference between the two can reasonably be ignored for such large, imprecise numbers anyway.

In fact, at least one site quotes a total biomass far higher than the number I used above:

http://www.regensw.co.uk/technology/biomass-faq.asp

Q. How much biomass exists? A. Worldwide, total biomass is a huge resource estimated as 1,250 billion tonnes of dry plant matter...

Another source puts the amount of oceanic cyanobacteria at 44 billion tons, a huge chunk of the earth's total living matter.

The best single 'big picture' overview of the world's biomass that I found comes from Wikipedia:

http://en.wikipedia.org/wiki/Biomass

Some other tidbits from around the web:

http://www.perceptions.couk.com/superants.html

Scientists say that about 15 percent of the Earth's total biomass _ the combined weight of all living things _ is composed of ants. Another 17 percent is taken up by termites

http://www.uwyo.edu/AgCollege/Strategic_Issues_files/Microbiology_plan.htm

Microbes...include the bacteria, archaea, fungi, protozoan and metazoan parasites, algae, and sub-cellular entities like viruses, viroids, and prions...are estimated to comprise over 50% of the total biomass on planet earth.

http://www.biologie.uni-hamburg.de/b-online/e54/54c.htm

More than 90 percent of the total biomass of the earth is made up by plants

http://www.delta-green.com/comint/dgml/v04/04-113.txt

Even quite conservative estimates suggest that the inclusion of all the microbes that are likely to be present beneath seafloor hydrothermal systems could double estimates of the total biomass on Earth

http://www.astrobio.net/news/article307.html

Dive deep beneath the sea; dig even deeper, hundreds of meters below the sea floor, and you'll find a hidden world of microscopic beings so numerous that they may make up a third of Earth's total biomass - as many as a billion cells per cubic centimeter of sediment.

http://www.szgdocent.org/resource/ff/f-rain1.htm

Rainforests account for half the world's total biomass!

The takeaway message here is that there's a huge tonnage of plants, bacteria, ants, termites and krill on this planet, and a piddling weight of human beings (though I'm the first to admit I could stand to lose a few pounds!).

search strategy -- Google searches on: "world's OR earth's OR planet's total biomass"

"total biomass * earth"

"total biomass" insects billion

"total biomass" insects

"total biomass" "1..1000 billion tons OR tonnes"

"world's OR earth's OR planet's total biomass"

also "global biomass" (17,000 hit)

whaling

fishing

submarines

midgit submarines, submarine tenders (cf supply and replenishment ships)

fairmiles

pirates

A mother ship, or mothership, is a larger vessel that looks after one or more smaller vessels. Some mother ships can also carry their "offspring".

The term originated in the early days of whaling and fishing,.

Subsets of populations (of bottlenose dolphinss) in Mauritania are known to engage in interspecific cooperative fishing with human fishermen. The dolphins drive a school of fish towards the shore where humans await with their nets. In the confusion of casting nets, the dolphins catch a large number of fish as well. Intraspecific cooperative foraging techniques have also been observed, and some propose that these behaviours are transmitted through cultural means. Rendell & Whitehead have proposed a structure for the study of culture in cetaceans,^[39] although this view has been controversial (e.g. see Premack & Hauser).

Fishing articles Importance Top High Mid Low None Total Quality A 1 1 2 Good article GA 1 1 B 2 5 3 3 13 Start 6 10 4 2 22 Stub 4 9 10 4 27 Assessed 3 16 23 14 9 65 Unassessed 4 3 165 172 Total 3 20 23 17 174 237

Ratio of "importance: What percent topics should be "top", "low" etc.

Paddy Ryan. Deep-sea creatures. Te Ara - the Encyclopedia of New Zealand, updated 21-Sep-2007 ++this is brilliant++

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Kite fishing is presumed to have been first invented in China. It was, and is, also used by the people of New Guinea and other Pacific Islands - either by cultural diffusion from China or independent invention.

Kites can provide the boatless fishermen access to waters that would otherwise be available only to boats. Similarly, for boat owners, kites provide a way to fish in areas where it is not safe to navigate such as shallows or coral reefs where fish may be plentiful. Kites can also be used for trolling a lure through the water.

Suitable kites may be of very simple construction. Those of Tobi Island are a large leaf stiffened by the ribs of the fronds of the coconut palm. The fishing line may be made from coconut fibre and the lure made from spiders webs.^[40]

Modern kitefishing is popular in New Zealand, where large delta kites of synthetic materials are used to fish from beaches,^[41] taking a line and hooks far out past the breakers. Kite fishing is also emerging in Melbourne where sled kites are becoming popular, both off beaches and off boats and in freshwater areas. The disabled community are increasingly using the kites for fishing as they allow mobility impaired people to cast the bait further out than they would otherwise be able to.

History

"Kite fishing is an old Oceanic method of troll fishing. The English traveller, Sir Henry Middleton, is said to be the first European to see kite fishing in the South Seas during his visit there from 1604 to 1606, and he introduced the kite in sports fishing in 1616. For this purpose kite flying astern of a moving boat were used, especially for tuna and other big game fish. The flying fish bait was securely tied to the hook. The fishing line lead from the rod to the kite and then back to the water. Thus the hook skipped realistically over the top of the waves. When a fish struck the bait, the line broke away from the kite and the fisherman was free to play the catch."^[42]

Kite towed longline

"The basic idea is very simple. When the wind id blowing offshore, a kite is used to tow out a line to which baited hooks have been attached.

"Kite fishing can be a lot of hard work. Sometimes you can get 25 fish on 25 hooks, and hauling them in takes a bit of muscle power.

"Can also use Kon Tiki rafts with square sails. Or, if the wind is strong enough, can use large, heavy weight plastic bags. Inflate by holding them intoi the wind. Then tie the open end with string and fasten the bag to a longline.

"But kites beat any other method hands down. A quality delta wind fishing kite has tremendous pulling poer, even in lighter winds. A kite can also be made to tack at an angle to the wind without much loss of pulling power. But it is important the kite is a quality one. Lesser kits will keep crashing into the sea, or as wind conditions fluctuate, they will not provide sufficient pulling power.

"Nowdays you can buy a battery powered torpedo shaped drone to use for towing your longline out to sea. These have the advantage that they do not depend on wind conditions".^[43]

"Quality contemporary kites are made from rip-stop nylon sail cloth. The spars are fibreglass and the overall finish and stitchings must be first rate".^[44]

Modern Fishing Kites

Kites for commercial fishing

Net-spreading underwater kites and kite vanes aid the control of large fishing nets. * Remotely-controllable paravane Robert A. Kirby et al

Kites for recreational, sport, and subsistence fishing

Kite applications#Kites for recreational, sport, and subsistence fishing

"There are several ways kites are used in recreatonal and sport fishing. Lofting drop lines is one, but things don't stop there. Net-spreading underwater kites, soil kites (kiting achors), kiting bait, control-kite trolling of bait, recreational kiting during fishing sessions, aerial photography of fishing environment using kites, and out and back cycles of trolling bait using a kite. Recreational fishing, commercial fishing, and scientific and military uses of depressors of tow lines use water kiting to accomplish the effects wanted."^[45]

George Webster wrote comprehensively on kite fishing.^[46][47]

A plan view of a Solomon islander's leaf fishing kite is shown in a photograph held by the Pitt-Rivers Museum is viewable at Natural History Magazine online; Pick from the Past, Natural History, April 1957: "Go Fly a Kite".^[48]