Nassau grouper

A Nassau grouper, E. striatus, ambushes its prey on Caribbean coral reefs.

The Nassau grouper is a medium to large fish, growing to over a meter in length and up to 25 kg in weight. It has a thick body and large mouth, which it uses to "inhale" prey. Its color varies depending on an individual fish's circumstances and environment. In shallow water (down to 60 ft), the grouper is a tawny color, but specimens living in deeper waters are pinkish or red, or sometimes orange-red in color. Superimposed on this base color are a number of lighter stripes, darker spots, bars, and patterns, including black spots below and behind the eye, and a forked stripe on the top of the head.

The Nassau grouper lives in the sea near reefs; it is one of the largest fish to be found around coral reefs. It can be found from the shoreline to nearly 100-m-deep water. It lives in the western Atlantic Ocean, from Bermuda, Florida, and the Bahamas in the north to southern Brazil, but it is only found in a few places in the Gulf of Mexico, most notably along the coast of Belize.[3]

It is a solitary fish, feeding in the daytime, mainly on other fish and small crustaceans such as crabs and small lobsters. It spawns in December and January, always around the time of the full moon, and always in the same locations. By the light of the full moon, huge numbers of the grouper cluster together to mate in mass spawning.

The Nassau grouper is fished both commercially and for sport; it is less shy than other groupers, and is readily approached by scuba divers. However, its numbers have been sharply reduced by overfishing in recent years, and it is a slow breeder. Furthermore, its historic spawning areas are easily targeted for fishing, which tends to remove the reproductively active members of the group. The species is therefore highly vulnerable to overexploitation, and is recognised as critically endangered on the IUCN Red List. The governments of the United States, the Cayman Islands, and the Bahamas have banned or instituted closed fishing seasons for the Nassau grouper in recent years. In the Cayman Islands, fishing in the spawning holes of the grouper has been banned until the end of 2016. In the case of the Bahamas, the government has instituted a closed fishing season in which fishing for the Nassau grouper is banned from December to February. It is in a very high rate decline and is at serious risk of becoming extinct.

A large spawning site for the species is located at Glover's Reef, off the Belizean coast. It has been identified as one of only two viable sites remaining for the species, of 9 originally known locations. In 2002, a permanent marine protected area was established on Glover's Reef. However, the Nassau grouper's spawning region is not included in this marine protected area (MPA). Instead, their spawning area (located north of the MPA) is subjected to a three-month closure during winter spawning aggregations.[4]

Many conservation methods have been put in place to help the grouper, including closed seasons, when fishing is not allowed. These seasons take place during the spawning season. Regulations allow only fish over 3 lb to be harvested to give the younger fish a chance to spawn. Some areas are protected, a complete ban on fishing the grouper in US waters has been instituted. Also, protection of the spawning sites at all times is in effect in certain places.

The U.S. National Marine Fisheries Service recently completed a review of the status of the species for Endangered Species listing.[5] They proposed to list the species as endangered.[6] However, analysis of declines in both populations as well as the size spawning aggregations has led to the species being uplisted to critically endangered by the IUCN Red List in 2018.[1]

Nassau grouper

Nassau grouper in Saba

The Nassau grouper has been depicted on postage stamps of Cuba (1965, 1975), the Bahamas (1971 5-cent), and Antigua and Barbuda (1987 40-c).

The threats to the grouper include overfishing, fishing during the breeding period, habitat loss, pollution, invasive species, and catching undersized grouper.

The Nassau grouper was placed on the World Conservation Union's redlist of threatened species in 1996, and it was determined to be endangered because its population has declined by 60% in the past 30 years. Over a third of spawning aggregations have been estimated to have disappeared, and the grouper is considered to be commercially extinct in some areas.

The current population is estimated to be more than 10,000 mature individuals, but is thought to be decreasing. Their suitable habitat is declining; they need quality coral reef habitats to survive. Their population outlook is not optimistic.

• http://www.oar.noaa.gov/spotlite/archive/spot_spawn.html
• http://www.flmnh.ufl.edu/fish/Gallery/Descript/NassauGrouper/NassauGrouper.html
• https://web.archive.org/web/20110103214238/http://www.reef.org/data/groupermoon.html

http://www.breef.org/Portals/0/Nassau%20Grouper%20notes.pdf

• Cornish & Eklund (2003). "Epinephelus striatus". IUCN Red List of Threatened Species. 2003. Retrieved 6 May 2006.old-form url Database entry includes a brief justification of why this species is endangered and the criteria used
• NMFS. Species of Concern Fact Sheet . 2008

• Fishbase species summary
• Photographs from Fishbase
• Cayman Islands close grouper spawning areas to fishing, citing sharp decline
• US National Marine Fisheries Service species summary including conservation measures
• Photos of Nassau grouper on Sealife Collection
• Nelson M. Ehrhardt, Vallierre K.W. Deleveaux, The Bahamas’ Nassau grouper (Epinephelus striatus) fishery- two assessment methods applied to a data-deficient coastal population, Fisheries Research 87 (2007) 17-27