Books by Michelle Schärer
UNA MIRADA AL MUNDO DE LOS PESCADORES EN PUERTO RICO: UNA PERSPECTIVA GLOBAL, 2011
Una mirada al mundo de los pescadores… presenta unos lineamientos en torno al desarrollo de la pe... more Una mirada al mundo de los pescadores… presenta unos lineamientos en torno al desarrollo de la pesca en Puerto Rico y sus posibilidades futuras. Por medio del análisis de diversos estudios socioeconómicos, ambientales y de pesquerías, así como las investigaciones del autor, este documento ofrece sugerencias y recomendaciones sobre asuntos críticos que deben ser considerados por todas las entidades y por los actores involucrados en la pesca, entre los que se destacan: las universidades, el gobierno local y federal, los científicos, el sector privado y los pescadores. Con frecuencia, los pescadores, los responsables de la formulación de la política pública y el público en general se preguntan: ¿Qué podemos hacer para promover la pesca en Puerto Rico? ¿Por qué no hacemos algo para impulsar tan importante actividad económica? ¿Por qué no explotamos los enormes recursos pesqueros que tenemos en nuestras aguas? En este trabajo, se intenta responder estas interrogantes mediante el análisis de datos, la búsqueda de información histórica y la proposición de alternativas y de posibles soluciones. La investigación de los factores ambientales, pesqueros, económicos y políticos, que les han dado forma a las pesquerías locales, constituye una pieza clave al momento de ofrecer las contestaciones. También, se examinan ejemplos de diversas partes del mundo que ayudan, de una forma u otra, a esclarecer nuestra situación con relación a la pesca y a ponerla en su justa perspectiva. El análisis de los factores y de los ejemplos señalados anteriormente contribuye, significativamente, a entender lo que ha sucedido en las pesquerías de Puerto Rico. Cabe destacar que la situación de las pesquerías globales es, en este momento, precaria. Durante muchos años, varias flotas pesqueras industriales han explotado, de manera inmisericorde, los recursos de distintos mares y regiones del planeta. Como consecuencia de la presión pesquera, sobre todo aquélla basada en tecnologías industriales, muchas especies han ido desapareciendo. La disminución de especies ha impactado adversamente a las comunidades pesqueras y amenaza a las culturas de pescadores por todo el globo, quienes son además desplazados por el turismo y por el desarrollo costero. Asimismo, el colapso de los abastos pesqueros ha provocado que los gobiernos reduzcan los subsidios para la pesca, ya que no quieren invertir en una actividad cuyo rendimiento económico va decreciendo. Los pescadores y los empresarios del sector han dependido de subsidios y de incentivos para mejorar las embarcaciones y obtener nuevas artes de pesca. Sin embargo, existe una moratoria global a esos subsidios. Ejemplo de ello es el caso de los Estados Unidos. En este trabajo se discute, críticamente, el asunto de la sobrepesca en Puerto Rico y se describen, desde una perspectiva histórica, los aspectos más sobresalientes de la actividad pesquera y de la cultura y la sociedad de los pescadores. También, se profundiza en el proceso de desarrollo de la pesca, aspecto al que por diversas razones históricas, económicas y ambientales, no se le ha prestado la atención que merece. Por consiguiente, se detallan los logros de los esfuerzos por desarrollar la pesca, entre los que se incluyen la motorización de la flota, la oferta de crédito para la compra de equipos y de motores y la construcción de las villas pesqueras. Este estudio plantea que en Puerto Rico nunca se dieron las condiciones óptimas para un desarrollo pesquero similar al de otros países del mundo, como es el caso de Cuba. A diferencia de estos países, el desarrollo pesquero de Puerto Rico, aunque de cierta importancia como es el área de Cabo Rojo, fue local y fragmentado. Si bien este tuvo su momento, de 1930 a 1990 aproximadamente, llegó a su fin. Muy bien pudo darse una pesquería importante de recursos pelágicos y de las especies llamadas altamente migratorias que son abundantes en la Zona Económica Exclusiva. Ese recurso fue explotado en gran escala por flotas estadounidenses, hasta muy recientemente. Ésa fue una oportunidad que perdimos. El caso del desarrollo de la pesca en Estados Unidos, por otro lado, se expone como ejemplo de desarrollo, pero también de una discusión en la que se debaten los niveles del progreso alcanzado y en la que se vislumbra un futuro no necesariamente halagador. En este estudio se esboza una lista de asuntos de extrema urgencia que deben ser atendidos para el bien de la pesca y de los pescadores de Puerto Rico. Por ejemplo: la situación precaria de los hábitats, el impacto del desarrollo sobre los ecosistemas, la amenaza de los huracanes y del cambio climático, el impacto del desarrollo sobre las comunidades pesqueras y su modo de vida, la competencia entre la pesca recreativa, deportiva y comercial, la agenda de varias organizaciones ambientales mundiales en contra de la pesca, la calidad de los datos sobre las capturas, la necesidad de integrar a los pescadores en el manejo de las pesquerías, la necesidad de entender el papel socioeconómico de la pesca, la necesidad de transferir, de manera precisa, la información técnica disponible a los participantes de las pesquerías y la comprensión de los procesos de injusticia ambiental. Finalmente, aquí se plantean una serie de pasos a seguir en la formulación de una política pública ideal en torno al desarrollo de la pesca.
Mention of trade names or commercial products does not constitute endorsement or recommendation f... more Mention of trade names or commercial products does not constitute endorsement or recommendation for their use by the United States government.
USING LANDSCAPE ECOLOGY TO DESCRIBE HABITAT CONNECTIVITY FOR CORAL REEF FISHES
Some coral reef fishes depend on specific habitats to complete ontogenetic migrations. The distri... more Some coral reef fishes depend on specific habitats to complete ontogenetic migrations. The distribution of these nursery species may be influenced by the connectivity between nursery habitats, used during early life stages, and coral reefs. The lack of nursery habitats can potentially limit the development or presence of fish populations depending on the nature of the fish-habitat relationships. Mangroves and seagrasses have been shown to support the ecological nursery function; therefore the lack of mangroves at a remote oceanic island (Mona, Puerto Rico) presents an opportunity to explore habitat connectivity at the island scale. Landscape composition and habitat configuration were tested to explain the presence and abundance of ontogenetic stages of reef fishes. Mona Island’s insular shelf was sampled by quantifying habitat metrics and fishes in 613, randomly stratified belt-transects (60 m2). Nursery habitats (nearshore seagrass, hardbottom (bedrock), coral reef) were species-specific and cross-shelf ontogenetic migrations were identified for the coral reef fish assemblage. When compared to La Parguera (with abundant mangroves and seagrass), the presence and abundance of some species at Mona were limited. A notable exception was Lutjanus apodus, which occupied nearshore hardbottom at Mona during juvenile stages. Habitat metrics correlated with fish density at distinct spatial scales and varied between species, suggesting ontogenetic requirements are species-specific and scale dependent. Depth, substratum vertical relief as well as percent cover of some epi-benthic groups were important correlates to fish abundance for the different ontogenetic stages. At landscape scales, areas with small patches (~100 m2) of coral habitat located in proximity to each other supported higher fish densities, although their arrangement on the shelf influenced this relationship. The distribution and replication of key habitats within Mona Island’s marine reserve suggest that this protection is sufficient to encompass inter-habitat connectivity for reef fishes. However, the limited distribution of nursery habitat in nearshore areas implies that land-based threats may present greater potential impacts to juvenile fishes. Landscape ecology served to detect patterns of habitat use and ontogenetic connectivity of reef fishes applicable to evaluating the ecological value of a particular arrangement of habitats within spatial-based protection.
Papers by Michelle Schärer
Advances in Marine Biology, 2014
The marine managed areas (MMAs) of the U.S. Caribbean are summarized and specific data-rich cases... more The marine managed areas (MMAs) of the U.S. Caribbean are summarized and specific data-rich cases are examined to determine their impact upon fisheries management in the region. In this region, the productivity and connectivity of benthic habitats such as mangroves, seagrass and coral reefs is essential for many species targeted by fisheries. A minority of the 39 MMAs covering over 4000 km 2 serve any detectable management or conservation function due to deficiencies in the design, objectives, compliance or enforcement. Fifty percent of the area within MMA boundaries had no-take regulations in the U.S. Virgin Islands, while Puerto Rico only had 3%. Six case studies are compared and contrasted to better understand the potential of these MMAs for fisheries management. Signs of success were associated with including sufficient areas of essential fish habitat (nursery, spawning and migration corridors), year-round no-take regulations, enforcement and isolation. These criteria have been identified as important in the conservation of marine resources, but little has been done to modify the way MMAs are designated and implemented in the region. Site-specific monitoring to measure the effects of these MMAs is needed to demonstrate the benefits to fisheries and gain local support for a greater use as a fisheries management tool.
Population Structure and Phylogeography in Nassau Grouper (Epinephelus striatus), a Mass-Aggregating Marine Fish
PLoS ONE, 2014
To address patterns of genetic connectivity in a mass-aggregating marine fish, we analyzed geneti... more To address patterns of genetic connectivity in a mass-aggregating marine fish, we analyzed genetic variation in mitochondrial DNA (mtDNA), microsatellites, and single nucleotide polymorphisms (SNPs) for Nassau grouper (Epinephelus striatus). We expected Nassau grouper to exhibit genetic differentiation among its subpopulations due to its reproductive behavior and retentive oceanographic conditions experienced across the Caribbean basin. All samples were genotyped for two mitochondrial markers and 9 microsatellite loci, and a subset of samples were genotyped for 4,234 SNPs. We found evidence of genetic differentiation in a Caribbean-wide study of this mass-aggregating marine fish using mtDNA (FST = 0.206, p<0.001), microsatellites (FST = 0.002, p = 0.004) and SNPs (FST = 0.002, p = 0.014), and identified three potential barriers to larval dispersal. Genetically isolated regions identified in our work mirror those seen for other invertebrate and fish species in the Caribbean basin. Oceanographic regimes in the Caribbean may largely explain patterns of genetic differentiation among Nassau grouper subpopulations. Regional patterns observed warrant standardization of fisheries management and conservation initiatives among countries within genetically isolated regions.
Fish sound production and acoustic telemetry reveal behaviors and spatial patterns associated with spawning aggregations of two Caribbean groupers
Regional abundances of Nassau grouper Epinephelus striatus and yellowfin grouper Mycteroperca ven... more Regional abundances of Nassau grouper Epinephelus striatus and yellowfin grouper Mycteroperca venenosa have declined due to overfishing of their spawning aggregations, prompting permanent and seasonal fisheries closures in the US Virgin Islands (USVI). As both species produce sounds associated with reproductive behaviors (courtship-associated sounds;CAS), passive acoustic and acoustic telemetry methods were used to determine temporal patterns of reproductive activity, site usage, and fish movements in order to assess the effectiveness of current management strategies at 2 marine protected areas (MPAs) in the USVI: the Grammanik Bank (GB) and Hind Bank Marine Conservation District (MCD). Patterns of sound production and ultrasonic acoustic tag detections showed that both species formed spawning aggregations from January through May at the GB, highlighting the current seasonal regulations (1 February to 30 April) as insufficient for protecting spawning stocks during the entire reproductive season. Acoustic tagging confirmed connectivity between the GB and MCD and exposed the broad extent of habitat used, including non-protected areas, during the spawning season. Spawning did not likely occur within the MCD, but the MPA did support abundances of calling individuals during spawning periods, indicating that both species produce CAS away from their spawning sites. This finding coupled with the detection of routine migrations between spawning and non-spawning sites presents a potential mechanism to lead conspecifics to the aggregation site and thereby increase reproductive fitness and spawning output.
Marine Managed Areas and Associated Fisheries in the US Caribbean
The marine managed areas (MMAs) of the U.S. Caribbean are summarized and specific data-rich cases... more The marine managed areas (MMAs) of the U.S. Caribbean are summarized and specific data-rich cases are examined to determine their impact upon fisheries management in the region. In this region, the productivity and connectivity of benthic habitats such as mangroves, seagrass and coral reefs is essential for many species targeted by fisheries. A minority of the 39 MMAs covering over 4000 km2 serve any detectable management or conservation function due to deficiencies in the design, objectives, compliance or enforcement. Fifty percent of the area within MMA boundaries had no-take regulations in the U.S. Virgin Islands, while Puerto Rico only had 3%. Six case studies are compared and contrasted to better understand the potential of these MMAs for fisheries management. Signs of success were associated with including sufficient areas of essential fish habitat (nursery, spawning and migration corridors), year-round no-take regulations, enforcement and isolation. These criteria have been identified as important in the conservation of marine resources, but little has been done to modify the way MMAs are designated and implemented in the region. Site-specific monitoring to measure the effects of these MMAs is needed to demonstrate the benefits to fisheries and gain local support for a greater use as a fisheries management tool.
Measuring the effectiveness of a Caribbean oceanic island no-take zone with an asymmetrical BACI approach
Sounds associated with the reproductive behavior of the black grouper (Mycteroperca bonaci)
Marine Biology
Passive acoustic and synchronous video recordings were made at two spawning aggregation sites to ... more Passive acoustic and synchronous video recordings were made at two spawning aggregation sites to study the sounds associated with reproductive behaviors of Mycteroperca bonaci. A characteristic sound was produced during courtship displays involving behaviors commonly observed for groupers of this genus at aggregations. The sound has a short pulsing section followed by a longer tonal portion with a mean peak frequency below 100 Hz. Courtship-associated sounds were quantified over one spawning season at Mona Island, Puerto Rico. Most of the daily sound production occurred during a period of 2 h prior to sunset. The highest rates of sound production lasted for a period of 10 days with lunar periodicity over three consecutive months coincident with the reported season of reproduction. Passive acoustics provide a tool to measure the variability of the reproductive activity of M. bonaci over time and may provide a method to evaluate current strategies designed to protect multi-species spawning aggregations that are critical for the recovery of threatened groupers.
Distribution, prevalence, and genetic analysis of Panulirus argus virus 1 (PaV1) from the Caribbean Sea
Inter-Research Disease of Aquatic Organisms
The pathogenic virus Panulirus argus virus 1 (PaV1) was first discovered in Caribbean spiny lobst... more The pathogenic virus Panulirus argus virus 1 (PaV1) was first discovered in Caribbean spiny lobsters Panulirus argus from the Florida Keys (USA) in 1999 and has since been reported in Belize, Mexico, and Cuba; its distribution in the wider Caribbean is unknown. We collected tissue samples from adult spiny lobsters from 30 locations in 14 countries bordering the Caribbean Sea and used molecular diagnostics to assay for the presence of PaV1. PaV1 occurred primarily in the northern areas of the Caribbean, where its prevalence was highest. The virus was not found in lobsters from the southeastern Caribbean, and its prevalence was lowest in the southwestern Caribbean. DNA sequence analysis was performed on a fragment of the viral DNA to examine the genetic diversity of PaV1 on a Caribbean-wide scale. Sequence variation in the viral DNA fragment was high, with 61 unique alleles identified from 9 areas. The sharing of viral alleles in lobsters from distant locations supports the hypothesis of a strong genetic connectivity among lobsters within the Caribbean, and further supports the hypothesis that postlarvae infected with PaV1 may serve to disperse the virus over long distances.
Sound production associated with reproductive behavior of Nassau grouper Epinephelus striatus at spawning aggregations
Sound production by Nassau grouper Epinephelus striatus is described from different spawning aggr... more Sound production by Nassau grouper Epinephelus striatus is described from different spawning aggregation sites in the Caribbean. Passive acoustic data and video were recorded in Belize (February 2011) and Puerto Rico (February 2012) revealing 2 distinctive sounds. The first is a pulse train sound thought to be associated with alarm or warning behavior, while the second is a tonal sound associated with reproductive behaviors, including courtship displays. The average peak frequency of the pulse train was 77.4 ± 30.3 Hz, individual pulse duration was 0.09 ± 0.02 s and the number of pulses varied from 6 to 13. For the tonal sound, the average peak frequency was 99.0 ± 33.6 Hz, and sound duration was 1.6 ± 0.3 s, ranging from 0.9 to 2.3 s. Long-term recordings at the Grammanik Bank, US Virgin Islands (February 2011) revealed variability in the daily patterns of tonal sounds during the residence time at the aggregation. Sound production was highest 7 to 8 d after the full moon between 20:00 and 21:00 h Atlantic Standard Time. The Nassau grouper courtship-associated sounds provide an advantageous tool to study the dynamics of spawning aggregations that are critical for the recovery of this Endangered species.
Sound Production and Reproductive Behavior of Yellowfin Grouper, Mycteroperca venenosa (Serranidae) at a Spawning Aggregation
DOI: 10.1643/CE-10-151, 2012
Reproductive behaviors and sound production of the Yellowfin grouper (Mycteroperca venenosa) are ... more Reproductive behaviors and sound production of the Yellowfin grouper (Mycteroperca venenosa) are described from in-situ observations by divers as well as synchronous underwater audio-video recordings at a spawning aggregation off Mona Island, Puerto Rico. The highest abundances of M. venenosa estimated from underwater visual surveys were detected in March and April, five to nine days after the full moon (DAFM). Four distinct color phases were observed for M. venenosa; two of these were unique to the spawning aggregation and one, the white-headed phase, was exhibited during interactions with other conspecifics corresponding to courtship displays. Variations in color phases during fish interactions and group formation coupled with sounds preceded spawning, which occurred near sunset. Low-frequency (<150 Hz) sounds produced by M. venenosa were variable yet they were classified into two types, pulsed and tonal. Both types of sounds were associated with reproductive behaviors although not linked to spawning rushes. These sounds were most frequent between 1800 and 2100 h, peaked the eighth DAFM, and ceased between 11–13 DAFM. Temporal patterns in sound production suggest that peak reproduction occurred in April followed by a smaller aggregation in May of 2010. The association of passive acoustics with reproductive behaviors for M. venenosa provides a tool to help identify spawning aggregation sites and monitor spawning stock abundance to evaluate the effectiveness of management and conservation efforts for this Near Threatened grouper.
Annual spawning aggregations of red hind Epinephelus guttatus form at predictable times and locat... more Annual spawning aggregations of red hind Epinephelus guttatus form at predictable times and locations and have historically succumbed to overfishing. Monitoring the status and restoration of aggregations is essential for evaluating the effectiveness of fishery management measures. Passive acoustic and diver-based underwater visual census (UVC) techniques were used to develop an efficient method for estimating red hind density from sound production at spawning aggregations. Red hind sound production was recorded from November 2010 to April 2011 at Abrir la Sierra, Puerto Rico. UVC surveys were conducted during the spawning season to assess changes in red hind density over a fixed time and area. Sound recorded from 18:00 to 19:00 h Atlantic Standard Time (UTC − 4) was representative of total daily changes in red hind sound production and was selected for the development of an efficient density estimation model. Pronounced daily changes in sound production and density were observed after the December 2010 and January 2011 full moons. Two hourly sound level measurements were compared to densities estimated by UVC surveys, yielding significant linear regressions, which were used to predict changes in fish density as measured at the aggregation site. Passive acoustic methods allowed to predict changes in red hind density and habitat use at a higher temporal resolution than previously possible with traditional methods. Red hind sound production and inferred densities can be monitored and analyzed efficiently for multiple aggregation sites simultaneously, documenting short-term and long-term changes in red hind densities at spawning aggregation sites and providing important information for the support or development of management strategies.
ABSTRACT Most large groupers form spawning aggregations at predictable locations and times, resul... more ABSTRACT Most large groupers form spawning aggregations at predictable locations and times, resulting in their susceptibility to overfishing and other ecological threats. Research, management, and enforcement of such aggregations could be enhanced if their exact locations were known. Traditional detection methods of diver and catch surveys are time consuming, especially when considering multiple species and sites.
Sound production by red hind Epinephelus guttatus in spatially segregated spawning aggregations.
Many fishes, including groupers, produce sounds associated with mating behavior; recording and an... more Many fishes, including groupers, produce sounds associated with mating behavior; recording and analyzing the occurrence of these sounds can provide long time-series records of grouper use of spawning habitat. Red hind Epinephelus guttatus sound production was recorded on spawning aggregation sites off the west coast of Puerto Rico and at Mona Island, Puerto Rico. Audio-video recordings were used to identify a species-specific sound produced by male red hind, most commonly during territorial patrols, and also during interactions with females. This sound is low in frequency (50 to 400 Hz) and consists of a series of pulses repeated at a variable rate. Long-term acoustic recorders were placed off the west coast of Puerto Rico at Abrir La Sierra and at Mona Island to record the timing of red hind sound production from January through March. Red hind sounds were detected at all times of the day, with peaks in sound production just before dusk. Monthly peaks in sound production were evident in each time series, but the monthly peak in sound production at Abrir La Sierra was 6 d later than the peak at Mona Island, suggesting that the timing of spawning of these 2 aggregations, while on a lunar schedule, was not broadly synchronized during this time period. This research lays the groundwork for both long-term monitoring and mapping of red hind spawning sites that will be useful for managing spawning aggregations, especially in remote areas.
ABSTRACT Fish spawning aggregation sites should be integrated into the design of marine reserves ... more ABSTRACT Fish spawning aggregation sites should be integrated into the design of marine reserves (MR) that seek to conserve biodiversity and manage local fisheries. Field research conducted since 2005 at Mona Island, Puerto Rico has provided useful data for this purpose. The remote islands of Mona and Monito are enclosed in the largest marine protected area and MR (no-take zone) in Puerto Rico.
ABSTRACT Surveys have been conducted since 2005 on a multi-species grouper spawning aggregation a... more ABSTRACT Surveys have been conducted since 2005 on a multi-species grouper spawning aggregation at Mona Island, Puerto Rico. Over two years, red hind (Epinephelus guttatus) and yellowfin grouper (Mycteroperca venenosa) were found aggregated and exhibiting signs of spawning activity (distended abdomens, unusual coloration, and peculiar behavior).
Passive acoustic detection of grouper sound production
Journal of The Acoustical Society of America, 2008
Passive acoustic recordings were used to study the behavior of red hind (Epinephelus guttatus) at... more Passive acoustic recordings were used to study the behavior of red hind (Epinephelus guttatus) at spawning aggregation sites off of Puerto Rico and Mona Island, and goliath grouper (Epinephelus itajara) and red grouper (Epinephelus morio) on the West Florida Shelf. The sounds produced by each species were unique, low‐frequency pulsed sounds and associated with reproductive‐related behavior. Male red hind produced sounds composed of a series of pulses that graded into a tonal‐like sound, mostly during territorial ...
ABSTRACT Coral reef fishes use a variety of habitats throughout daily, ontogenetic, and spawning ... more ABSTRACT Coral reef fishes use a variety of habitats throughout daily, ontogenetic, and spawning migrations, therefore requiring a suite of habitats to complete their life cycle. The use of multiple habitats by grunts (Haemulidae) and snappers (Lutjanidae) was investigated at Mona Island, a remote island off western Puerto Rico. The objective of this study was to determine if the distribution of three different life stages was random in relation to benthic habitat types.
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Books by Michelle Schärer
Papers by Michelle Schärer