Goliath Grouper

This topic submitted by Stephanie Bistritz ( bistrisc@miamioh.edu) at 2:49 PM on 6/5/08.

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Tropical Field Courses -Western Program-Miami University

Stephanie Bistritz
Marine Ecology 2008
Goliath Grouper

The Goliath grouper lives up to its name weighing in at up to 800 pounds. This massive fish belonging to the family Serranidae is the largest of its family. Many people have heard the common term grouper used to refer to many different species. This name is referring to the subfamily Epinephelinae. The goliath grouper has captured the attention of conservationists, fishermen, and tourists alike due to its unique characteristics. It is currently a threatened species for many reasons including its size, reproduction and lifespan. These reasons make fishing this grouper very easy which has lead to over-harvesting. This grouper is vital to conservation throughout the mid-Atlantic. Since this species is protected it allows many other species to fall under its protection as well. From the mangroves to the coral reefs this species is important in managing and protecting many areas from destruction.

The Goliath grouper is the largest grouper in the Atlantic weighing up to 800 pounds. Full grown groupers are over two meters long. The size of the grouper alone makes it an easy target for spear fishing. The grouper lives a long time, the oldest grouper was a female that was 37 years old (World Conservation Union, 2007), although there may be older groupers in areas that are not heavily fished.

Reprodution of the grouper occurs in the months from July through September. Typically 100 groupers gather in shallow waters and release sperm and eggs into the water. Although starting in the 1970s the number of groupers joining together to spawn drastically reduced. From the late 1970s to 2000 scienctists would see around ten to twenty groupers together mating. Once the egg is fertilized and hatches the fish take five to six years to reach sexual maturity. The jueveniles live close to shore in mangroves or in seagrass beds before heading out to the coral reefs or a suken ship as adults.

The goliath grouper is found off the coast of many countries throughout the mid Altantic and up to west coast of the United States and Mexico. Here is a map of where the Goliath grouper is found.

The Goliath grouper is braided into Davidson’s web by living in the same areas that are essential to the tiny polyps and fish that live on the reefs. Mangroves are essential for the juvenile grouper; it seeks protection and nourishment from the mangroves. This is an ongoing problem due to the destruction of the mangroves. There is very little mangrove left in Florida due to the channelization to redirect freshwater flow from the Everglades, mosquito-abatement, and development for agricultural, industrial, and residential purposes. Since mangroves are important in the juvenile stages of the Goliath grouper it could affect the population recovery even if reproduction levels of adult fish are successful (Coleman and Koenig, 2006). These mangroves serve as an estuary for the juveniles of many fish not only the Goliath grouper. Protecting this environment would mean protecting many species and the success of life on the coral reefs.

The mangroves are vital in the survival of the Goliath grouper, with the nutrients and protection that the grouper attains from living in the mangroves. That is all part of the food web. According to Leopoldo et al., doing a study on local knowledge on the Goliath grouper understanding the food web is important in understanding conservation (2006). As juveniles the Goliath groupers have predators such as barracuda, king mackerel, moray eels, other groupers, sandbar sharks and hammerhead sharks. The large adults have very few natural predators (Robins). They feed on crustaceans, such as spiny lobsters, shrimp and crab. They also eat stingray, parrot fish, octopus and young sea turtles. The grouper is intrinsically sown into the food web changing its position from a young fish to the head of the web as an adult. The food web as Leopoldo et al. said, is very important in understanding conservation. By protecting one species we are ultimately protecting many species and habitats at the same time.

The protection of this species was due to a number of reasons. The main reason was human induced over fishing. But humans fish many species and they are not all on protection lists, this is because of certain characteristics that the Goliath grouper has. The first is the large size of the grouper. This makes the grouper an easy target for fishermen. The Goliath grouper is hunted by spear fishing, and hook and line. Both of these techniques make the grouper an easy catch. This fish has been around for hundreds of years and has been used as food for over two hundred years. So why are we now seeing a significant decline in the population? Kim Iverson and the South Atlantic Fishery Management Council have three reasons to why this population has been declining so rapidly in the past thirty years. The first reason is in the 1970’s fishing substantially declines because of advanced electronics. These gadgets could target and locate where big fish were hiding making it very easy to catch and harvest a Goliath grouper. The second reason is that the market price on grouper increased. Knowing that the Goliath grouper is the biggest of its kind it brought in the most profit for the commercial fishermen. The last reason is spear fishing because more popular. Spear fishing for Goliath grouper is very easy seeing that this fish has tendencies to lay low on the reef floor, or near a sunken ship, in relatively shallow waters.

Other reasons for over fishing are due to the habits of the Goliath grouper. Reproduction as talked about early occurs in groups of one hundred or more, this makes these large fish easy targets for commercial fishermen. They harvest tenfold what they would fishing for them out in the open ocean. They also live at shallow depths and reproduce at shallow depths making it easy to harvest them.

The Goliath grouper is on the list as a concerned species in many countries. The United States stopped harvesting the Goliath grouper in 1990, the Caribbean followed in 1993. In 2002 Brazil set up a five year protection plan restricting the harvesting to only subsistence fishing (Iverson, 2006). Although these countries along with many other countries have stopped the harvesting of the Goliath grouper there are other dangers that are threatening the survival of the grouper. There is so much habitat loss due to marine agriculture, and freshwater agriculture. There is the destruction of the mangroves and edge areas, due to farming, housing and fisheries. Harvesting is also a problem, with high market prices and local food sources. The Goliath also has intrinsic factors such as slow growth rate, and late sexual maturity. Lastly there are many direct human impacts like tourism and recreational use of their habitat.

With all the factors that are working against the Goliath grouper the protection of the fish is working in some areas. The Herald Tribune had an article published May 25, 2008 stating that the Goliath grouper is making a comeback in the Gulf of Mexico. The World Conservation Union has taken the fish off the ‘critically endangered” species list although it is continuing protection of the species. There are two dangers for this once critically endangered species. The first danger is poachers which have continually been a threat but the World Conservation Union predicts that those numbers will increase. The second threat is the catch and release. With growing numbers of Goliath groupers the amount being caught by accident will increase which causes the fish great stress. But overall the World Conservation Union is very positive with the recovering species, and hoping that it will continue along this path.

This species is so important to protect because its survival means the survival of edge habitats, such as mangroves and grass beds, along with the strength of the coral reefs. This species is considered an umbrella species meaning that the survival of this species ensures the survival of species that are underneath it. Since its habitats are vast and it needs so many resources to become so large by protecting the Goliath grouper hundreds of other species and environments are protected. An umbrella species is similar to what Davidson talks about in the Enchanted Braid. The grouper is entangled into the mangroves to the reefs, the spiny lobster to the sharks. The braid that is woven along the life of the grouper entraps many species and by protecting the grouper the braid stays intact.

The Goliath grouper is a very interesting fish, living for over 35 years and weighing up to 800 pounds this fish is unique to the tropical waters. Its protection and survival looks good as we head into the 21st centaury. As long as we continue to be aware of destructive human habits and we use our resources wisely this fish will continue on the planet for generations to come.

Literature Cited:

Herald Tribune Goliath grouper makes comeback May 25, 2008.

Leopoldo et al.(2006). Local ecological Knowledge on the goliath grouper Epinephelus
itajara (Teleostei: Serranidae) in southern Brazil. Neotrop.ichthyol.vol. 4 no. 4.

Robins, R. Goliath Grouper. Florida Museum of Natural History Ichthyology
Department.www.flmnh.ufl.edu Accessed April 10, 2008.

World Conservation Union (2007). IUCN Red List of Threatened Species.
www.icunredlist.org Accessed May 22, 2008.

Coleman and Koenig, (2006). Goliath Grouper Epinephelus itajara, Characteristics,
Distribution and Abundance. Florida State University, Coleman and Koenig

Iverson, K. (2006). South Atlantic Fishery Management Council; News Release.
www.safmc.net Accessed May 22, 2008.

I will talk about the importance of the Goliath grouper, why people should care about this species. I will give some background to begin with, size, habitat. Then move onto why it is on some endangered species lists. What different protection plans certain countries have set up. I will end with the results that are happening due to the certain plans and how the future looks for this fish.

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