Atlantic Goliath Grouper, by Albert KOK via Creative CommonsDuring a recent visit to the Georgia Aquarium, a guide was sharing interesting facts about the “Tropical Diver” exhibit. This species is deemed critically endangered by the IUCN because of its reproductive issues (slow growth, late sexual maturity) and overfishing.
Groups like Florida State University’s Coleman & Keening Laboratory are promoting mangrove protection and trying to shift the public’s perception of the Goliath grouper as being nothing more than a big, lazy nuisance. 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. An adult can grow to more than a meter long, and weigh 25 kg They tend to be solitary daytime feeders, eating small fish & crustaceans Their large mouths are used to ‘inhale’ or suck in prey The coloring of an individual can vary from red to brown These fish have little black spots around the eyes (I’ve no idea why).
Credits: all photos, Melinda River; Infographic by Royal Defense Force (tip o’ the hat to Char Albury); Info Sheet, Dept of Fisheries Gulf grouper are large fish that live in shallow, coastal areas during their first 2 years of their life, before moving on to rocky reefs and kelp beds.
Gulf grouper used to be very common in the eastern Pacific Ocean, but they became scarce because commercial and recreational fisherman could easily catch them. Their abundance has severely declined since the mid-20th century primarily because of direct harvest by commercial and artisanal fisheries.
Outside a known population in Bahia Magdalena, there is no published evidence of gulf grouper along the Pacific coast of the Baja California peninsula. Current gulf grouper distribution appears to be much more limited than their historical range.
They gather at reefs and underwater mountains and form spawning aggregations from April to June. Activities that may degrade their habitat include the release of contaminants, such as urban runoff, wastewater, or oil and gas spills.
Pollution can also reduce the amount of oxygen in the water or deliver chemicals that are toxic to these fish. Physical barriers, such as shoreline and offshore development can also threaten gulf grouper by limiting their access to important breeding or feeding areas.
Overfishing Direct harvest of gulf grouper, especially at spawning aggregation sites, is the biggest threat to the species. First, adult gulf grouper gather in large groups at the same time every year to reproduce.
Additionally, gulf grouper likely start life as females but later transition into males. This means that there are fewer male groupers left in the oceans, which makes reproduction more difficult.
It lives in shallow tropical waters at small depths that range from 16 to 164 feet (5 – 50 meters) among coral and artificial reefs. The Atlantic Goliath grouper can grow until it reaches approximately 8.2 ft (2.5 m) long and it weighs about 790 lb (360 kg).
Although the Atlantic Goliath grouper seems to be scary for its large size and even wide mouth, it is not extremely dangerous but it is courageous. Being fearless and delicious at the same time is not good for this fish as these two factors are the main reasons behind making it highly sought after by fishermen and thus harvesting it in large numbers.
Treating this fish in such a cruel way was the main reason behind making it endangered and this is why it was necessary to protect it and entirely ban harvesting it. The Atlantic Goliath grouper is fearless which means that it is not scared easily and this is why it attacks different creatures in the sea even divers and the 11 feet lemon sharks.
The Atlantic Goliath grouper eats most of what it can attack and this includes barracudas, octopus, fish, young sea turtles, crustaceans and even sharks. The aggregation of large numbers of the fish in a small area during the spawning season attracted commercial and sports fishermen to the species.
Mosquito control measures and water drainage projects in the Everglades have both impacted heavily on the Florida mangrove swamps. The loss of the waterways making up part of its nursery will not aid in the recovery of Goliath grouper numbers.
A rapid increase in dinoflagellates of the species Karina breves is responsible for the marked color change of the sea. As well as changing the color of seawater, Karina breves produces a neurotoxin, called breve toxin, which is deadly to many fish.
“This shows that over-fishing could decimate another major food and economic resource for humans, similar to the loss of the cod stocks off New England and Canada that has put thousands of people out of work,” said Roger McManus, a senior director of Conservation International’s Marine Program. A study published earlier this year found that the trade is significantly depleting reef fish populations off northern coast of Borneo.
“The results are worrying and highlight the urgent need for fishery management, more effective marine protected areas (MPA's), and more sustainable eating habits for consumers of these fishes,” said Dr. Yvonne Saxony, Chair of the IUCN Grouper and Wrasse Specialist Group and Associate Professor at the University of Hong Kong. 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.
Image credit: OAR/National Undersea Research Program/Public domain Nassau grouper, a reef fish, is one of the critically endangered species found within the Gulf of Mexico. While seen occasionally in the Gulf of Mexico, groupers are often found further south, in the Caribbean territories where reefs are plentiful.
They are predatory fish which feed indiscriminately on reef life, but have also been targeted by fishers across Mexico, the Caribbean and Central America. Image credit: Kris Mikael Kristen/Wikimedia.writhe Hammerhead Shark is so named for the distinctive hammer like shape of its head.
It is a brutal process which has been hard to curb, and has played a major part in the continuing decline of the species. Image credit: palindrome6996/Wikimedia.writhe yellow-headed Amazon, or Amazon matrix is an endangered species of parrot which lives in Mexico and parts of Central America.
Its bright green color and distinctive yellow head give the Amazon that classic look often associated with pet parrots. While there are restrictions on owning these parrots domestically, their popularity as pets has drastically impacted their populations in the wild.
Image credit: Andrea Menotti/Shutterstock.Comte whale shark, scientific name Rincón types, is an endangered species with a decreasing population trend, according to the IUCN Red List. The Whale Shark is the largest fish in the world, measuring upwards of 60 ft., and can live for approximately 80 years.
The whale sharks have a wide territory, living mostly in the open sea and can be found anywhere from the Gulf of Mexico, to the Philippines. Image credit: magical/Wikimedia.relisted as critically endangered on the Icon red list, the Hawks bill turtle, or Eretmochelys imbricate is continuing to see a decrease in its global population.
They are one of the more well-known species of turtle visually speaking, and their shells have the mottled look that has given name to the famous ‘tortoiseshell’ pattern. This once prominent marine creature has also seen threats from a variety of other sources, from tourism and recreation, to fishing, oil and gas drilling, and even to a lesser extent, climate change.
Both poaching and habitat loss have contributed to the decline of tapir populations in the wild, and the species is now listed as Endangered. Conservation and rehabilitation efforts have proven difficult, largely due to the animal’s low reproductive rate.
A tapir has an average gestation period of 400 days, and only carries one offspring at a time, meaning any attempts to increase breeding are a long and slow process. Thankfully, due to their large size, the Baird Tapirs have very few natural predators, so a human change in how we see and care for these animals and their habitat could see an improvement in their population given time.
Image credit: Tom Rather/Shutterstock.Comte Mexican Prairie Dog, Comes Mexicans, is endemic to Mexico, and has not been found or introduced anywhere else in the world, outside of captivity. They favor the Mexican Plateau, and much like other prairie dog species, arid grassland valley habitats.
They dig and spend much of their time within an intricate burrow system, where they form fairly large social colonies. Agriculture has been one of the greatest detriments to the Prairie Dog population, both in terms of land modification and cattle herding, which can erode soil and reduce the abundance of suitable grasslands.
Additionally, the turtles run the risk of being caught in tow-lines and fishing nets which can trap and kill adults in the wild. Image credit: Paula Olson, NOAA/Public domain Aquila, or phenomena sing, has been called the world’s rarest marine mammal, and holds a Critically Endangered status on the Icon Red List, with a decreasing population.
Once caught, a large sea mammal can easily become entangled and snared, causing trauma or death. Image credit: dispale/Wikimedia.this tiny rabbit species, Romerolagus Diaz, is native to Mexico, and lives in the mountainous, or volcanic regions.
Farming, infrastructure and afforestation have all infringed on the natural grasslands these rabbits call home, forcing them in to smaller and more segmented areas across Mexico. The slow but steady temperature increase in the area has also been a factor, forcing the rabbits to seek higher altitudes.