Nassau Groupers

As part of Green Reef’s Nassau Grouper Research and Advocacy Campaign, this week’s Reef Brief highlights the morphology and life history of this important commercial species.

Nassau Groupers are generally identified by four to five irregular dark stripes on a pale tan or gray body, black dots around their eyes, a large black saddle patch on their tail and a wide “tuning-fork” pattern on their forehead. They grow to lengths of approximately three feet and weigh around 55 pounds. As adults, these top-level predators are usually found near shallow, high relief coral reefs and rocky bottoms to depths of 90 meters. They have the ability to change color to camouflage themselves with their surroundings.


A close-up of the endangered species, the Nassau Grouper.
Nassau Groupers exhibit no sexual dimorphism in body shape or color, so it is impossible from a glance to determine if a particular fish is male or female.

Nassau Groupers, as are many other type of groupers and coral reef fishes, are solitary during most of the year and then come together to spawn in large aggregations. These aggregation banks are site specific, usually in 20-40 meters of water at specific locations at the outer reef shelf where temperatures are between 25- 26º Celsius. In Belize, Nassau Groupers have historically aggregated around the full moons of December and January in groups that can contain upwards of several thousand individuals. During these aggregations, the female groupers produce planktonic eggs that are fertilized externally. The reproductive success of the eggs is thought to be affected by predators and currents.

Why do they need protection? There are several factors which make the Nassau Grouper especially vulnerable to over fishing. Nassau Groupers come together in large groups, called spawning aggregations, during the full moons of December and January. Fishermen are familiar with these cycles and find that the best time to catch this species is when they are in these large spawning groups. The spawning aggregation sites are generally in the same location year after year which makes it easy for fisherman to return to the sites. The fish also take a long time to reach maturity, which means that if a large number of mature adults are fished from the population one year, it will take a long time before the population can return to normal. The size of the population can also be negatively affected if the fish are caught before they have had the chance to spawn. These characteristics combined with the relatively strong demand for grouper fillet and roe (eggs) suggest that some measures need to be taken to ensure that this fishery does not collapse.


Coloration of the Nassau grouper blends in with its physical environment.
This situation is not one that exists just in Belize. Populations of Nassau Groupers in the Caribbean are reported to be declining and some countries (Bermuda, U.S. Virgin Islands and Puerto Rico) have even gone as far as to close this fishery in order to protect them from extinction. Several countries, including the Dominican Republic, have specific closed seasons for the Nassau Grouper in an effort to protect the species when they are most susceptible to fishing pressures. Other countries, including Mexico and the Cayman Islands have instituted gear restrictions. Belize has made several efforts at conserving this species, including establishing marine reserves at some of the spawning aggregations, but due to the continued decline in annual catches, it is clear that additional measures may be needed to protect this species and the fishery that it supports.


Predators of the Nassau grouper include large fish such as barracuda, king mackerel, moray eels, and other groupers. The sandbar shark, below, and the great hammerhead shark are also known to feed on groupers.
Help being offered

Aside from developing a Nassau Grouper Research and Advocacy Campaign, Green Reef has hosted a full day workshop in Belize City entitled Working Towards Sustainable Management of Nassau Groupers in Belize.

During this workshop several presentation where made and following these sessions all those attending got briefed on the current status of the fishery, a panel-lead discussion provided a means by which all attendees were able to voice their opinions regarding the need for urgent management and also look into alternatives for fishermen who rely on the income that fishing the Nassau Grouper aggregation provides. In order to more fully review the possible options and develop consensus among all user groups, NGO’s and the Fisheries Department, the idea of a Spawning Aggregation Working Group was formed.

Members that were nominated to sit on this working group included Green Reef, The Nature Conservancy, Beverly Wade and Dwight Neal (Belize Fisheries Department), National Fisherman’s Co-op, Caribeña Co-op, Alfonso Nuñez, Placencia Co-op, Belize Tourism Board, Belize Tourism Industry Association, TIDE and a representative from the fishing community in Punta Gorda. Terms of Reference outlined the actions that the group would work toward and a time frame for action were established that allow consultations, public review and further discussion to occur before the December and January spawning moons.

Green Reef is confident that this working group will provide the means by which to assure full participation of all stakeholders so that whatever management measures that are suggested and implemented are those that are the most effective for protecting the Nassau groupers while keeping the interests of fisherman in high priority.

For more information on Green Reef please contact us at 226-3254 or email us at :greenreef@btl.net.

As part of its continued efforts to promote responsible and sustainable use of Belize’s marine resources, Green Reef developed a Nassau Grouper Research and Advocacy Campaign. Green Reef announced that they had been awarded a grant from the United Nations Development Program, Global Environment Facility/Small Grants Program (UNDP GEF/SGP). This grant funded a significant portion of this very valuable project.

In order to better understand the state of the Nassau Grouper populations in Belize, Green Reef coordinated video surveys at nine sites during the spawning period in January last year. Below is a re-count by videographer Joe Miller of the video survey conducted by Green Reef.

Green Reef study shows Grouper numbers declining
by Joe Miller

Every year, during the full moons of December and January, thousands of Nassau Grouper come together to spawn. Fishing during this time is so popular in Belize that it has diminished both the size and numbers of these fish. Green Reef has put a plan in motion to quantify the problem through observation of the aggregations, and measuring and weighing of fish actually caught. It was my pleasure to be selected to go along as a photographer and observer to aid in documenting this endeavor.

Seven different expeditions traveled to the best-known grouper spots in Belize to monitor fishing activity. Our expedition was led by Mito Paz, local director of Green Reef. A valuable volunteer was Dan Ellison, who also works for Green Reef. Dan Wagner, a well-known underwater videographer from Florida and I made up the photo crew. Our expedition left for Rendezvous Point on Turneffe Atoll on the morning of January 8th in the 25 foot skiff, “Ceci,” piloted by Captain Victor Lara. We set up our dive and scientific camp adjacent to the fishing camp at Rendezvous. This gave us convenient access to the dive site, as well as the ability to measure and weigh the daily grouper catch.

The stories I had heard over the years had piqued my interest in making this journey. Old-timers had told me of thousands of Nassau Groupers in giant columns, many feet deep, the females releasing their eggs into the water as the males converged to fertilize them. I was soon disappointed. The large numbers are not there. The Nassau Grouper population is not only diminished from all accounts; it’s only a tiny fraction of what it used to be. The cause is fishing during the spawning season. Commercial fishermen know that when these masses of fish flesh come together, there is no better time to snag them for resale. Our group saw small gatherings of fish, 4-8 at the most.

There were a few exceptions where we saw maybe 10 or 12, but those sightings were rare. Fishermen are especially rewarded with their catch this time of year. The fertile females contain sacks of roe, or eggs that sell for $6-8 per pound. The rest of the fish sell in the market in Belize City for $2 per pound. The average daily catch this year seemed to be about 300 pounds of fish with maybe 15-20 pounds of roe. In effect, fishermen are rewarded not only for depleting the resources during a vulnerable time, but for cashing in on the future, as well. No eggs to fertilize...no fish next year. We Belizeans, both born and naturalized, fully understand the value of a season for conch and lobster to allow them to reproduce. Heavy fines are levied against those who take from our future. Raise up your voices to help Green Reef lobby to put in a season for Nassau Grouper. Surely we can work together to sustain this vital part our fragile ecosystem-which brings in tourism dollars-while reaching a compromise with the fishing industry.

Thanks to Amigos del Mar, Offshore Express and Turneffe Flats for logistical, transportation and emergency support.

Reef Brief is a weekly column published in the San Pedro Sun

For more information on Green Reef please contact us at (email: greenreef@btl.net or telephone us at 226-2833.

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