Last month we successfully conducted our 19th year of the Grouper Moon Project. Around the winter full moons each year, our field team joins forces in the Cayman Islands to study one of the last remaining, and largest currently known, spawning aggregations of the endangered Nassau Grouper. Since 2001, REEF and the Cayman Islands Department of Environment have collaborated on this project. Along with our academic colleagues from Scripps Institution of Oceanography and Oregon State University, the Grouper Moon Project includes research, monitoring, and outreach efforts aimed at understanding and protecting this iconic species.

The 2020 Grouper Moon Project took place from February 5-19. During the two weeks, our team conducted annual monitoring to estimate the number and sizes of grouper attending the aggregations on both Little Cayman and Cayman Brac, documenting spawning behavior in Nassau Grouper as well as other species that use the site for spawning, and researching fertilization and survival rates of eggs and larvae. We also piloted a new study to document the presence of fish DNA in water samples as a potential new means to monitor aggregation sites. This year we were joined by teams from NOAA and Konsberg Maritime for testing a sonar-like system for estimating fish populations. The Little Cayman Nassau Grouper aggregation provides a unique opportunity to evaluate the use of this technology, which if proven, will provide a valuable tool for harder-to-survey aggregation sites, like those on Grand Cayman and elsewhere in the Caribbean.

In addition to research and monitoring, the Grouper Education Program engaged students at several local Caymanian schools, as well as others abroad in schools and the Shedd Aquarium in Chicago. As part of the education program, our team participated in three live-from-the-field webchats to explain the work of the project and share the economic, ecologic, and cultural importance of Nassau Grouper as a top predator on Caribbean Coral Reefs. All live-feeds are archived and available to view on REEF’s YouTube channel,

To find out more about the project, view videos, and read the latest scientific publications from the work, visit We greatly appreciate the support of local businesses in making the project possible, including the Southern Cross Club and Little Cayman Beach Resort and Reef Divers.