The Nassau grouper is one of the Caribbean’s most iconic fish species.
The Department of Environment told Cayman 27 Little Cayman’s spawning aggregation is now the largest in the Caribbean, but little Cayman’s success story did not write itself overnight.
The grouper moon project, a collaboration between the DOE and Reef Environmental Education Foundation (REEF) is now in its 17th year, making it the longest-running continuous research project on the species in history.
DOE Senior Research Officer Croy McCoy told Cayman 27 this year’s SPAG was among the largest in the project’s history, with an estimated 5,000 to 7,000 individuals participating.
Over the last decade, scientists on the project have recorded the dramatic rebound at the Little Cayman SPAG, and the data shows the population estimates picking up steam beginning in 2012. REEF’s Dr. Brice Semmens called it a population explosion.
Now, the scientists behind the Grouper Moon project are trying to find out how Little Cayman’s success can be replicated in Cayman Brac and Grand Cayman.
“This year we’ve had a huge amount, more individuals, more grouper then we have had in previous years,” said Dr. Semmens.
Thousands of Nassau grouper gathered at the spawning aggregation on Little Cayman’s west end…
Grouper moon scientists estimate between five to seven thousand individuals participated in the iconic species’s annual reproductive rites.
“From where we were seven or eight years ago, I think the population has more than tripled, and what’s really cool is that a lot of the fish that we are seeing out there are the really young ones, the ones that it’s their first time at the aggregations,” said Dr. Semmens.
“Little Cayman is a complete success story,” said Mr. McCoy.
Mr. McCoy said while the populations at Cayman Brac’s east end SPAG have a long way to go to match the Little Cayman SPAG, the Brac’s Nassau grouper are on the right track.
“We have watched the population come from like a few hundred to where it was like a thousand now, and hopefully it will follow the same pattern Little Cayman followed,” said Mr. McCoy.
When the Little Cayman SPAG was ‘rediscovered’ in 2001, Mr. McCoy told Cayman 27 the population was comparable to today’s.
“It was mesmerizing and overwhelming,” he recalled of the dive in which he and former DOE Research Manager Phil Bush came upon the Little Cayman site.
But the following year, the SPAG was no longer under the radar for fishermen.
“They fished the aggregation that year, and they fished them down pretty low, from that down to about 1500 fish, 12 to 1500 fish,” he said. “It was basically too much to sell, for the fisherman, and a lot of that year’s spoiled. There was a big public outcry on that, and that prompted the Marine Conservation Board and the government to have a lockdown, and alternate years for fishing.”
From then, he said populations remained mainly flat until Little Cayman’s major recruitment pulse in 2012. He says the Brac could be due for a similar recruitment event in coming years.
“Under the current management plans and strategies we have in place, we hope that it will be a thriving population, like Little Cayman is, over the next decade,” said Mr. McCoy.
The Grouper Moon project’s success in Little Cayman and the positive signs starting to show in Cayman Brac have not yet translated to Grand Cayman’s Nassau grouper.
Mr. McCoy told Cayman 27 the Grand Cayman SPAG is “beyond struggling.” He said researchers are finding it a challenge to even locate Nassau grouper, even with the help of an remotely-operated-submersible.
He said these low population SPAGs become even more vulnerable to fishing, as the fish tend to spend more time at the site.