The Grouper Moon Project is a conservation science partnership between REEF and the Cayman Islands Department of Environment (DoE), with scientists from Scripps Institution of Oceanography at UC San Diego and Oregon State University. The project is aimed at studying Nassau Grouper, Epinephelus striatus, a keystone species on Caribbean coral reefs. Since 2002, our team has studied the Nassau Grouper spawning aggregations in the Cayman Islands, which hosts some of the largest and last known gatherings of this endangered fish. Our efforts have resulted in the successful recovery of Nassau Grouper populations in the Cayman Islands, and the project highlights the value of collaborative efforts for conservation success.
As the winter full moon approaches and we prepare for our annual field season, we wanted to share some of the highlights of Grouper Moon research findings over the last 23 years. Read on to learn more. You can also visit www.REEF.org/groupermoonproject to see details on education programs, scientific studies, and documentaries about the Grouper Moon Project.
One of the earliest scientific papers from the Grouper Moon Project was published in the journal Environmental Biology of Fishes in 2004. This paper documented the characteristics of the newly discovered Nassau Grouper spawning aggregation in the Cayman Islands. The authors provided visual and video documentation of four nights of spawning of Nassau Grouper, the description of the fish's nighttime movements and color phase shifts, and the documentation of courtship and spawning behavior in ten additional species. A few years prior to this paper being published, former REEF staff member Leslie Whaylen was leading a REEF Field Survey Trip in Little Cayman, around the same time that fishermen discovered the aggregation of Nassau Grouper off the west end of the island. As a result, approximately 2,000 fish were harvested in 10 days, from a population that was later determined to be approximately 9,000 fish. After meeting with the Cayman Islands government, the Grouper Moon Project was formed.
A few years later, in 2007, lead scientist for the project Dr. Brice Semmens, along with project partners, published a paper that explored why Nassau Grouper had declined so drastically in the Caribbean, and what could be done to reverse the trend. The discussion leaned heavily on early findings from the Grouper Moon Project. This study, titled "Charting a Course for Nassau Grouper Recovery in the Caribbean: What We’ve Learned and What We Still Need to Know" was presented at the 60th Gulf and Caribbean Fisheries Institute Meeting.
In 2020, almost two decades after the spawning aggregation was first discovered, a landmark paper was published in the prestigious Proceedings of the National Academy of Sciences that presented our findings of conservation success for endangered Nassau Grouper. Results of the analysis showed that on both Little Cayman and neighboring Cayman Brac, Nassau Grouper spawning aggregations have more than tripled in response to adaptive management by the Cayman Islands government over a decade. These management actions were a direct result of research conducted as part of the Grouper Moon Project.
The Grouper Moon Project is the Caribbean’s oldest continuous grouper spawning aggregation research program, and represents one of the most advanced, multi-faceted tropical fisheries research programs in the world. The project aims to support science-informed policies that will facilitate healthy grouper fisheries in the Cayman Islands in the coming years, while maintaining the Cayman Islands’ global leadership in collaborative tropical fisheries research and management. Since 2001, REEF and our collaborators have published 22 scientific papers sharing results from the research. You can see the full list of papers here.