[Photo] The square-tailed coral trout (Plectropomus areolatus) is considered threatened. (Credit: J. E. Randall: Conservation International)

Science Daily ??? The first comprehensive assessment of the world’s 162 species of grouper, a culinary favorite and important commercial fish, found that 20 are threatened with extinction unless proper management or conservation measures are introduced. Eight species previously were listed by the World Conservation Union (IUCN) as under extinction threat, and the new assessment proposes adding 12 more.

A panel of 20 experts from 10 nations determined the extinction threat facing groupers, which are the basis of the multimillion-dollar live reef food fish trade based in Hong Kong and comprise one of the most valuable groups of commercial fishes in chilled fish markets of the tropics and sub-tropics. Around the world, consumers pay up to $50 per kilogram for grouper.

“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.

The ground-breaking workshop at the Department of Ecology and Biodiversity of the University of Hong Kong was the first systematic assessment of the commercially important species, said Dr. Yvonne Sadovy, Chair of the IUCN Grouper and Wrasse Specialist Group and Associate Professor at HKU.

“The results are worrying and highlight the urgent need for fishery management, more effective marine protected areas (MPAs), and more sustainable eating habits for consumers of these fishes,” said Sadovy, who organized the workshop.

The workshop is part of a worldwide study of marine life called the Global Marine Species Assessment (GMSA) by IUCN, Conservation International and numerous other partners that provides scientists with baseline data for analyzing threats to ocean species.

“This assessment forms part of a growing focus on over-fishing and conservation concerns for fishes in general,” said GMSA Director Kent Carpenter.

The workshop identified the need to better protect outer reef areas and to manage spawning aggregations of many of the threatened grouper species. Outer reef areas are often not incorporated into MPAs, and spawning aggregations necessary for continued reproduction of many grouper species are rapidly eliminated by uncontrolled fishing. Increasing international trade to meet an insatiable demand for grouper poses a particularly major threat.

The workshop outcome serves as another reminder of the need for sustainable fishing and consumption of important fish species. The threatened groupers are naturally vulnerable to over-fishing, and the continued decline of fish populations can threaten food security and livelihoods in source countries. Their pending inclusion on the IUCN Red List of threatened species also reflects the widespread failure to successfully manage fisheries associated with coral reefs.

Groupers are among the oldest fish on coral reefs, with some species reaching more than 50 years old. Several species only reach reproductive maturity later in life, making them particularly vulnerable to fishing before they mature. In addition, commercial fishing that targets reproductive gatherings of adults further hinders replenishment of unmanaged populations.

The threatened groupers include two species of coral trout grouper, which are mainstays of the live reef food fish trade in Hong Kong. Both can be found in Hong Kong fish markets, but they face heavy and unmanaged fishing pressure that is rapidly reducing their populations.

In North and South America, heavy fishing of grouper for the chilled fish markets also poses a significant threat. The Nassau grouper, once one of the most commonly landed groupers in the islands of the Western Atlantic Ocean, now is listed as Endangered under the U.S. Endangered Species Act and has virtually disappeared from most Caribbean reefs.

Note: This story has been adapted from a news release issued by Conservation International.