They engulf prey whole by opening their large mouths, dilating their gill covers, rapidly drawing in a current of water, and inhaling the food. Large sharks and carnivorous marine mammals prey on adult red grouper.
Red grouper are found in the western Atlantic Ocean from Massachusetts through the Gulf of Mexico and south to Brazil. Annual catch limits are used for red grouper in the commercial and recreational fisheries.
These fisheries are closed when their annual catch limit is projected to be met. Both the commercial and recreational fisheries have size limits to reduce harvest of immature red grouper.
The commercial and recreational fishing seasons are closed from January through April to protect red grouper during their peak spawning period. To reduce by catch, there are restrictions on the type of gear fishermen may use and where they can fish.
Year-round and/or seasonal area closures for commercial and recreational sectors to protect spawning groupers. Its range includes the Gulf of Mexico and Florida Keys in the United States, the Bahamas, most of the Caribbean, and most of the Brazilian coast.
Scientists from our Southeast Fisheries Science Center are working to understand the changes that have occurred in coral reef ecosystems following the loss of top predators, such as groupers. From 1997-2005, our researchers collaborated with Florida State University's Institute for Fishery Resource Ecology (Dr. Chris Koenig and Dr. Felicia Coleman) to monitor the status and recovery of Goliath grouper.
This Goliath grouper research program investigated juvenile and adult Jewish abundance, distribution and migration patterns; their age and growth; and their habitat utilization. With the help of Don Maria we have tagged over 1,000 adult Jewish and have observed aggregations of Goliath grouper in both the Gulf of Mexico and more recently, the South Atlantic.
Posters created by the Center of Marine Conservation help disseminate information about our project and its requirements, highlighting our tagging study and the morphology of Goliath grouper. Given that these groupers were afforded protected status, researchers worked to utilize and develop novel non-lethal techniques to procure and analyze biological samples for life history information.
Researchers have also determined that soft dorsal rays hold promise for aging older fish (Marie et al., 2008). These casualties, resulting from red tide, gave our biologists a unique opportunity to collect a multitude of biological samples, without having to sacrifice healthy animals.
From these decomposing carcasses, biologists were able to record length for use in an age/length relationship, and were able to extract monoliths and remove dorsal spines and rays for comparison of hard parts in age and growth analysis. Tissue samples were also removed and sent to the Florida Marine Research Institute, so they could evaluate the level of red tide toxin.
The sampling trip gave these biologists an opportunity to educate the curious beach goers about red tide and Goliath grouper (a few of which had been misidentified as baby manatees). Attempts to evaluate the data needed to assess the status of these depleted stocks and develop rebuilding plans present unique challenges.
In 2010, the Florida Fish and Wildlife Conservation Commission and NOAA Fisheries convened a benchmark Goliath grouper assessment for the continental U.S. population. This project would not have been possible without ongoing collaboration with researchers from Florida State University, Everglades National Park, and the recreational fishing and SCUBA diving communities.
Which is why there are closed seasons for certain fish, ensuring a time when they can be left alone to breed in peace and to perpetuate their species. They are mostly found in the Northern Bahamas but only the Nassau grouper is on the IUCN Red List as an Endangered Species in need of protection.
Sad to say, mankind is the main cause of the population fragility that has led to the official listing, and the imposition of a strict closed season for 3 months between December 1st and February 28th. Scientific studies have shown that commercial overfishing has reduced a thriving population to fewer than 10,000 mature fish.