REEF recently concluded the annual field season for the Grouper Moon Project, a highly successful conservation science collaboration between REEF and the Cayman Islands Department of Environment (DOE) to study one of the largest and last known spawning aggregations of endangered Nassau Grouper in the Caribbean.  The research team, made up of REEF staff and volunteers, along with our collaborators from DOE, Scripps Institution of Oceanography, and Oregon State University, conducted daily dives on the aggregation off the west end of Little Cayman, and visited the an active aggregation on Cayman Brac. The team documented the number and size of fish gathered at the aggregation using a variety of methods, including stereo-video, tag counts, and video pans. The team has also developed a novel project called "GrouperSpotter" which uses facial recognition and AI to document individual fishes that visit the aggregation each year. To connect Caymanian students with the project, our education team hosted live-from-the-field webchats with local classrooms, and including a virtual dive with our scientists. These livefeed chats are archived and available for viewing on the REEF YouTube channel. The education program has been in place for more than 10 years and has become a crowning achievement of the project. You can read more about the Grouper Education Program later in this issue. Visit to see links to videos and photos, and to read about the scientific publications and legislative actions that have been informed by this work.

Preliminary modeling results suggest that the aggregation is approaching 9,000 Nassau Grouper, which is a fourfold increase since 2010. This year, the Nassau Grouper spawned nightly for four nights, starting three nights after the January full moon. The fish stay at the aggregation site for about 10 days before migrating back to their home sites around the island. Because this is the only time of year these fish reproduce, protecting the spawning aggregation from harvest is critical. Research findings from the Grouper Moon Project supported science-based legislation passed by the Cayman Islands government in 2016 that prohibits fishing for Nassau Grouper during the spawning season, and the Cayman Grouper Conservation Law serves as a blueprint for other conservation efforts in the region.

The Grouper Moon Project has been underway since 2002. Funding is provided by REEF members and several foundations, and many dedicated volunteers have assisted with fieldwork through the years. Generous logistical and financial support is provided every year by Caymanian businesses and locals, including Peter Hillenbrand, Southern Cross Club, Little Cayman Beach Resort, Reef Divers, and Jason Belport. We also appreciate continued support from Berkley White and Backscatter Photo and Video, and Marissa Wiganowske and Pegasus Thuster DPV for field assistance. Ocean Technology Systems and Backscatter provided discounted gear and expertise for a new underwater communication system used for the educational livestreams. REEF greatly appreciates Grouper Moon team member Tom Sparke for helping build the new communication system and for serving as the camera operator during this year's livesteamed dives. Funding for the new communication equipment was provided by the Cayman Islands government.