New study suggests electrochemically-induced Alkalinity Enhancement can enhance coral growth rates  - NOAA/AOML Chris Malanuk Published on: March 4, 2026 On Posted on March 4, 2026 March 6, 2026 by Chris Malanuk to Corals Ocean Chemistry and Ecosystems New study suggests electrochemically-induced Alkalinity Enhancement can enhance coral growth rates In a new study led by scientists at NOAA’s Atlantic Oceanographic and Meteorological Laboratory ( AOML ) and the Cooperative Institute for Marine and Atmospheric Studies ( CIMAS ), a novel form of alkalinity enhancement (AE) was demonstrated to significantly enhance the growth rates of corals, a finding that could promote the scaling of coral reef restoration. Coral reef structures face a variety of rising environmental stressors: ocean acidification, rapidly-spreading coral diseases excessive nutrient runoff and marine heatwaves . As scientists investigate the thresholds of coral species to these stressors, they are also exploring strategies to optimize the success of ongoing restoration Restoration practitioners today nurture coral fragments on small, shallow nurseries before actually outplanting them back onto the reef.  Because corals produce only a few centimeters of calcium carbonate skeleton each year, researchers are seeking ways to enhance coral growth rates and scale up restoration, a goal complicated by ocean acidification . This lowering of the ocean’s pH not only accelerates reef erosion but decreases the coral’s ability to grow (i.e. calcify) Today, AE is being explored as a way to help accelerate coral growth. Alkalinity helps seawater resist changes in pH and increases the relative abundance of the ions that corals need to grow. While commonly studied forms of AE involve introducing alkaline minerals such as olivine to seawater, scientists at AOML exposed coral fragments to increased alkalinity concentrations generated by electrolysis, a technique known as electrochemically-induced alkalinity enhancement (eAE). With eAE, an electric current drives a chemical reaction in which water molecules separate, producing hydroxide ions that elevate alkalinity. This process ultimately makes the water immediately surrounding the source of the current less acidic (or more basic), creating a microenvironment benefitting corals as they produce new layers of their hard calcium carbonate skeleton. With support in funding from NOAA’s Coral Reef Conservation Program (CRCP) , Patrick Kiel, a Ph.D. candidate at the University of Miami working with AOML’s Coral Program, designed and conducted an eAE investigation within the Experimental Reef Lab . Kiel applied a low voltage electrolytic system acros four tanks to deliver alkalinity to corals growing on the small steel cathodes while removing the acid generated at the anode. Essentially, this system produced a microenvironment on each cathode where the pH was elevated compared to the rest of the aquaria. System designed to expose A. cervicornis (I) and two size-classes of P. clivosa (short, J; tall, K) on a set of steel plate cathodes (F) to electrochemically-induced alkalinity enhancement (eAE). See Kiel et al. (2026) for more information. Using these systems, Patrick exposed fragments of two key reef-building species, the critically-endangered Acropora cervicornis (Staghorn coral) and two sizes of Pseudodiploria clivosa (Brain coral), to eAE over a sixty day period. He monitored changes in the seawater chemistry, coral calcification rates, and production of new planar tissue to determine if the height of the coral affected the impact of the treatment. While A. cervicornis fragments showed no changes in growth rates, the small fragments of P. clivosa exposed to eAE had a 43% higher calcification rate and produced new tissue at a growth rate 53% greater compared to those not exposed to eAE. Importantly, enhanced growth was only observed among the shorter P. clivosa fragments that were completely within the elevated pH microenvironment produced by the electrolytic system. Coral fragments of both species branching beyond the microenvironment showed no significant growth rate enhancements, conveying how the benefits of eAE can only be found among corals completely within the small region immediately above the steel cathode. “This study could have true implications for coral nurseries and outplanting,” explains Patrick Kiel. “If eAE is implemented for corals that fit within the enhanced microenvironment, such as the microfragments and juveniles commonly used by our restoration partners, we can minimize the time these corals spend in the nursery. This allows practitioners to outplant larger corals, helping them avoid predation and reach sexual maturity faster than they currently do.” The AOML Coral Program is conducting this research in concert with efforts to identify coral species and specific genets that prove most resilient to environmental stressors . While ongoing experiments to study and enhance the resilience of corals to extreme conditions provide one piece of the puzzle, innovating ways to optimize restoration and accelerate growth is the key to expand ongoing restoration to the scale needed today, alongside efforts to reduce and effectively mitigate environmental stressors globally. As the study conveys, electrochemically-induced alkalinity enhancement may be one technique to push the boundaries of protecting and restoring invaluable coral reefs. This project was supported by the University of Miami, the National Science Foundation Grant No. 1938060, and NOAA’s Coral Reef Conservation Program (CRCP) Tags Coral Health and Monitoring coral reefs Coral Restoration and Resilience Previous Previous post: Antarctic Bottom Water contraction drives abyssal ocean warming along SAMBA-West line (34.5°S) in the Argentine basin Next Next post: Scientists at AOML lead workshop for international Surface Ocean CO2 Reference Observing Network (SOCONET)