Grouper Moon Project
A collaborative conservation program between REEF and the Cayman Islands Department of the Environment
Nassau grouper (Epinephelus striatus) - a social and ecological corner stone of Caribbean's coral reefs Grouper Moon Research To Be Greatly Expanded in 2008-2010
Thanks to a three-year grant from the Lenfest Ocean Program at the Pew Charitable Trusts, REEF and our collaborators at the Cayman Islands Department of the Environment (CIDOE) and Oregon State University (OSU) will greatly expand the conservation science research being conducted as part of the Grouper Moon Project in the Cayman Islands. The funded research, broadly titled as "The reproductive biology of remnant Nassau grouper stocks: implications for Cayman Islands Marine Protected Area (MPA) management" will evaluate the potential for spawning site MPAs to recover Nassau grouper stocks.
Check out the 2008 image gallery to see images and video from this year's research.
What is the Grouper Moon Project?
Normally solitary and territorial, during the winter full moons grouper travel, sometimes over great distances, and “group” together to spawn. About fifty of these spawning aggregations sites have been recorded in different places throughout the Caribbean. Historically, once discovered, grouper aggregation sites have become synonymous with fisherman aggregation sites. Due to the timing and site fidelity of the spawning aggregations and the ease with which these relative loners can be caught while congregating by the hundreds and thousands to spawn, one-third to one-half of the known Caribbean aggregation sites are now inactive. The Cayman Islands used to be home to five Nassau grouper (Epinephelus striatus) spawning sites. Today, four of these sites are dormant or depleted. But one site, on the west end of Little Cayman Island, is home to one of the last great reproductive populations of this endangered species.
In the Winter of 2002, REEF launched a ground breaking expedition to the Cayman Islands - the Grouper Moon Project. The Project’s objectives were to observe the Nassau grouper spawning aggregation off the western tip of Little Cayman, and to develop a protocol for monitoring their numbers and activity at the site. For two weeks, a team of divers from REEF and the Cayman Islands Department of Environment visited the aggregation site and nearby reefs. Since that first year, REEF has coordinated annual efforts to monitor and study the Little Cayman Nassau grouper aggregation. The project has grown in scope to include an ambitious acoustic tagging research project, juvenile habitat and genetics studies, and early results have been published in the scientific literature.
A wide-angle view of the aggregation in 2003. Photo by Phil Bush, click to view a larger version. 
Showing the different spawning colorations seen in Nassau grouper. Photo by Phil Bush, click to view a larger version.
Grouper Moon Acoustic Research Project
How effective are no take areas on spawning grounds? - A research project initiated in 2005. Visit the project's website to view methods, learn more about the research team, see preliminary results, and watch videos of Nassau grouper movement to and from the aggregation.
Yearly Project Summaries
Click here to read annual summaries of the Grouper Moon research.
Published Results
This paper summarized the first five years of monitoring of the Little Cayman West End aggregation, including a summary of spawning activity, total numbers of fish present at the aggregation each year, coloration, and behavior. View PDF
This paper documents attacks by the isopod Excorallana tricornis tricornis on Nassau grouper caught in Antillian fish traps during the post-spawning season of Spring 2005. Fish were being trapped in order to acoustically tag individuals from sites around Little Cayman Island in order to better understand what percentage of reproductive-size individuals attend the aggregation each year. The paper discusses the apparent energetic costs associated with spawning. This work was also presented as a posted at the 56th Gulf and Caribbean Fisheries Institute Meeting in 2005 (View PDF), and a summary of the poster is posted online. (View Poster)
This paper summarizes the findings from the 2002 REEF Grouper Moon Project, which documented the characteristics of a newly discovered Nassau grouper spawning aggregation. View PDF
Videos
Click on the title to download the video. Formats and sizes vary, see end of description for details.
Grouper Moon Project Documentary - A 16 minute documentary video produced by Dr. Brice Semmens that highlights REEF's collaboration with the Cayman Islands Department of the Environment on this critical conservation science project. The acoustic tagging research that was initiated in 2005 is featured. (Windows Media Player, 33 MB).
Cleaning Station at the Aggregation - During the February 2006 aggregation, we placed stationary cameras on two active cleaning stations for one hour intervals during the day in order to record behavior and cleaning station activity. A compilation of time-lapse video from a cleaning station, sped up 2x actual speed, -- the video represents approximately 10 minutes over two days at one large sponge that served as an active cleaning station on the Little Cayman West End aggregation site. The Nassau grouper are seen flashing various colorations during their attempts to be in the primary cleaning location in the sponge. In addition to Nassau grouper, yellowfin grouper and tiger grouper occasionally show up to be cleaned (but rarely are allowed access for more than a few moments). (Windows Media Player, 12 MB)
Little Cayman Spawning Aggregation Compilation 2008 - This video is a compilation of activity at the West End Little Cayman spawning site. The clip features the large number of Nassau grouper at the site (estimated at 3,000-3,500 individuals) a few days prior to spawning, the use of the site by many different species to spawn (including horse-eye jack), Caribbean reef sharks that try to prey on spawning (and distracted!) fish, and finally the big event, Nassau grouper spawning. (Windows Media Player, 20MB)
Grouper Moon 2008 Compilation - This video/audio compilation was edited by Dr. Scott Heppell (OSU) and features topside and underwater footage of the January 2008 field research. (Windows Media Player, 50MB)
Current Drifter Tracks - Three satellite drifters were deployed at the Little Cayman aggregation site on the night of spawning. The paths will be recorded by ARGOS satellites for 45 days and the resulting data will be used to develop a larval dispersal model in collaboration with researchers from University of Miami. Little Cayman is the island shown. The video represents movement between 1/29/08 and 2/11/08. See the 2008 Project Summary for more information on this work. (AVI, 10MB)
Fish Movement - Preliminary results from the acoustic tagging project that was initiated on Little Cayman in 2005 to understand the movement patterns of Nassau grouper. This link will take you to a page with links to movement track videos of all tagged Nassau grouper.
Acoustic Tagging Methods - This link will take you to a page with several short video clips of the capture, tagging, release, and tracking methods used in the Grouper Moon Acoustic project.
2002 Little Cayman Spawning Aggregation - A short compilation of video from the first year of video documentation of the Little Cayman West End Aggregation Site in 2002. Footage includes daytime behaviors and spawning releases. (Windows Media Player, 10MB).
All videos, images and content from these pages are copyrighted by REEF/Grouper Moon Project. Viewing and/or downloading any content implies agreement to the terms of use. Appropriate photo/video credit and copyright information must be given and notification of their use must be provided to REEF.
Collaborative Team and Major Supporters
The Grouper Moon Project is a collaboration between REEF and the Cayman Islands Department of the Environment. REEF extends a huge thanks to the CIDOE staff for their tireless efforts, including Phil Bush, Croy McCoy, and Bradley Johnson. The Grouper Moon Project has continued through the years empowered by the first year’s success and the passion of project leader Leslie Whaylen.
REEF volunteer project team members have included: Brenda Hitt, Denise Mizell, Judie Clee, and Alex Score. Drs. Scott and Selina Heppell from Oregon State University started assisting with various Grouper Moon research projects in 2005.
Generous logistical support has been provided throughout the years by Peter Hillenbrand and Mary Ellen Cutts, as well as by local dive operators the Little Cayman Beach Resort, Southern Cross Club, Sam McCoy’s Diving Lodge, and Pirate's Point Resort. Funding for the acoustic work is provided by the NOAA International Coral Reef Conservation Program and PADI Project AWARE. Raymarine Marine Electronics donated RADAR equipment to assist the CIDOE in their enforcement efforts. A research grant from the Lenfest Ocean Program at the Pew Charitable Trusts is funding the project between 2008-2010. Additional funding has been provided by Franklin and Cassandra Neal, Ken Sinibaldi, Clive and Stella Wood.