Grouper Moon Project - 15th Year of Conservation Science in the Cayman Islands

Protecting a Caribbean Icon - Over 4000 Nassau Grouper gather at the spawning aggregation on Little Cayman. The site is protected during the winter months. Photo by Paul Humann.
REEF Grouper Moon team member, Dr. Scott Heppell, swimming in the aggregation. Numbers, sizes, behaviors are all documented. Photo by Josh Stewart.
Starting a few nights after full moon, the fish change colors to almost all bicolor and spawn. Spawning happens right at dusk, and occurs over several evenings. Then the fish all leave the site and go back to their home reefs for another year. Photo by Jim Hellemn.

REEF scientists and volunteers just wrapped up another season of the Grouper Moon Project, a collaborative research effort with the Cayman Islands Department of the Environment (CIDOE). In it's 15th year, this important project focuses on one of the largest (and one of just a few) known spawning aggregations of Nassau Grouper in the Caribbean. Over 4,000 grouper amass in one location for 7-10 days following winter full moons. Our team went to Little Cayman around full moons in both January and February this year (both because it was considered a “split year”, meaning the full moon dates were right on the line of predicting which month would be the strong spawning month). February turned out to be the big month, and spawning was seen over 3 nights starting 3 nights after full moon.

Several interesting video clips and stories from the field were posted on REEF's Facebook page. Be sure to check it out and like our page to keep updated on all REEF's programs.

Since 2002, REEF and our partners at CIDOE, Scripps Institution of Oceanography, and Oregon State University have used a variety of research techniques from diver surveys to state-of-the-art technology to study this amazing natural phenomenon. The research has yielded ground-breaking results that have led to improved conservation for Nassau Grouper in the Cayman Islands.

In addition to the research, REEF also is leading the charge on an educational program surrounding Nassau Grouper and spawning aggregations. Thanks to support from Disney Conservation Fund, we have created an exciting K-12 education curriculum rooted in the link between healthy reef communities (including humans) and healthy spawning aggregations. See last month's REEF newsletter for more about the Grouper Education Program.

Want to learn more about the Grouper Moon Project? Watch this short PBS documentary about our efforts. 

Many Thanks! The Grouper Moon Project wouldn’t be possible without the dedication, passion, and financial support from many individuals, Cayman Island businesses, and foundations. It truly takes a village to pull off this conservation research project. In 2016, we especially appreciate the continued generous logistical support provided by Peter Hillenbrand, and local lodging and dive operators Reef Divers & Little Cayman Beach Resort and the Southern Cross Club. Funding from the Disney Conservation Fund supported field efforts and the Grouper Education Program. FLOW Cayman Islands has provided support for the live-video feeds for the Grouper Education Project since 2012. Cayman Airways provided inter-island travel support. And the staff at Central Caribbean Marine Institute provided research space for the fertilized egg work. Thanks also to our scientists, REEF volunteers, and partners who made this year's efforts possible. It's impossible to list everyone here - please visit the Grouper Moon page to see the full list -

If you would like to support this important marine conservation program, please donate to REEF -

Design by Joanne Kidd, development by Ben Weintraub