New findings from the Grouper Moon Project reveal how technology can advance our understanding of changes in fish spawning aggregations due to conservation actions. The paper, published this year in ICES Journal of Marine Science, presents size data collected over a 17-year period at the Nassau Grouper spawning aggregation on Little Cayman. Fish usually need to be caught to be measured, but scientists from the Grouper Moon Project have used video camera systems to collect an impressive dataset on Nassau Grouper lengths. The authors combined these data with information on growth and abundance to produce a comprehensive assessment of Nassau Grouper on Little Cayman. Findings from this work revealed that Nassau Grouper recovered on Little Cayman largely thanks to exceptionally strong recruitment from the 2011 spawning season. Length data from Cayman Brac also showed signs of a strong 2011 year class, and substantial improvement in population status in recent years. The study and findings demonstrate that video camera systems can be an effective part of monitoring protected fish spawning aggregations.

The full citation of the paper is:

Stock BC, Heppell SA, Waterhouse L, Dove IC, Pattengill-Semmens CV, McCoy CM, Bush PG, Ebanks-Petrie G, and Semmens BX. 2021. Pulse recruitment and recovery of Cayman Islands Nassau Grouper (Epinephelus striatus) spawning aggregations revealed by in situ length-frequency data. ICES Journal of Marine Science. doi:10.1093/icesjms/fsaa221

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