6 March 2007
|Black grouper, near threatened due to fishing on its spawning aggregations Photo: (c) Craig Dahlgren/Bahamas National Trust. Photographed at Exuma Cays Land and Sea Park (Bahamas), where marine protected areas emphasize the non-consumptive use of resources
Twenty species of grouper, a globally important group of 162 coral reef food fishes, are threatened with extinction unless management or conservation measures are introduced.
This was the conclusion of a panel of twenty experts from 10 countries at a recent conservation summit convened to assess the status of groupers worldwide. Groupers are the basis of the multi-million dollar live reef fish market of the sea food trade centred in Hong Kong, where consumers can pay up to US$50 per kg for this delicacy. Groupers are also the most valuable commercial fishes in the fresh fish markets of the tropics and sub-tropics.
The workshop, held at the Department of Ecology & Biodiversity of the University of Hong Kong, is ground-breaking: “this is the first time that fishery data and population information for groupers have been globally and systematically assessed using IUCN criteria, with the worrying result that twenty species are threatened”, said Dr. Yvonne Sadovy, Chair of the IUCN Grouper and Wrasse Specialist Group and Associate Professor at HKU, who organized the workshop. “The results highlight the urgent need for better fishery management, more effective marine protected areas (MPAs) and more research on these important but vulnerable species” she added.
“The workshop forms part of a growing focus on the problems of overfishing, and conservation concerns for fishes in general, and will contribute to a massive new initiative, the Global Marine Species Assessment, led by the World Conservation Union (IUCN) and Conservation International. “We aim to examine the conservation status of all fishes, globally”, says Kent Carpenter, of Old Dominion University, Virginia, USA.
The need to better protect outer and deep reef fish populations and habitats, and the spawning (reproductive) aggregations of these species, was identified as being particularly important for a number of the threatened grouper species assessed. Outer and deep reef habitats are often not included in MPAs, and protection of spawning aggregations—critical to the maintenance of exploited populations of many threatened groupers are rarely incorporated in fishery management plans; they can rapidly eliminated by uncontrolled fishing. The increasing international trade of these reef fishes poses a major threat because of the insatiable demand (and resulting high prices) for groupers.
The workshop outcome serves as yet another reminder of the logical need to limit exploitation levels to the speed with which fish populations reproduce. The threatened groupers are naturally vulnerable to overfishing, and if fish populations continue to decline, this can threaten food security and livelihoods in source countries, as well as the species concerned. The listing of these species as threatened also reflects the widespread failure to successfully manage fisheries associated with coral reefs.
“Groupers are some of the oldest fishes on coral reefs – some groupers may be more than 50 years old – and several do not reach maturity until late in life, making them particularly vulnerable to fishing before they are able to reproduce” says Matthew Craig of the Hawaii Institute of Marine Biology. Add to this the fishing pressure on the spawning aggregations of adults, the targeting of juveniles for food and for capture-based mariculture and the ongoing loss of reef habitat worldwide, and there seems little opportunity for unmanaged populations to be replenished.
As just one example, two species of coral trout grouper (Plectropomus areolatus and P. laevis), mainstays of the live reef food fish trade in Hong Kong, and both species that aggregate for spawning, were listed as Vulnerable based on the IUCN Red List criteria. Although currently these species are seen in local Hong Kong markets, the heavy and unmanaged fishing pressure that they are exposed to is rapidly reducing populations and will continue to do so unless their fisheries are controlled. Groupers are so prized in Hong Kong and southern China, and so depleted on many corals reefs of SE Asia, that they are imported alive by air or sea, from as far away as south Pacific and the Indian Ocean.
And it is not just the live fish trade that threatens grouper species. In North and South America, heavy fishing for these highly desired food fish also poses a significant threat. As just one example, the Nassau grouper (Epinephelus striatus) is listed as Endangered; yet this was once one of the most commonly landed groupers in the islands of the western Atlantic.
While it has virtually disappeared from most Caribbean reefs, the species continues to be fished in many parts of its range and receives little effective management protection anywhere.
“Without conservation efforts, everybody loses: the loss of such species will affect not only fishermen and traders in source countries but also the local and international traders, and the people who like to eat them,” said Dr. Sadovy.
Photos and additional information are available from: yjsadovyhku.hk; Tel: 2299 0603 or Kent Carpenter kcarpentodu.edu
The IUCN Red List threat categories are the following, in descending order of threat:
- Extinct or Extinct in the Wild;
- Critically Endangered, Endangered and Vulnerable: species threatened with global extinction;
- Near Threatened : species close to the threatened thresholds or that would be threatened without ongoing specific conservation measures;
- Least Concern : species evaluated with a low risk of global extinction;
- Data Deficient : no evaluation because of insufficient data.
The World Conservation Union (IUCN)
The World Conservation Union is the world’s largest conservation network. The Union brings together 82 States, 111 government agencies, more than 800 non-governmental organizations (NGOs), and some 10,000 scientists and experts from 181 countries in a unique worldwide partnership. The Union’s mission is to influence, encourage and assist societies throughout the world to conserve the integrity and diversity of nature and to ensure that any use of natural resources is equitable and ecologically sustainable. The World Conservation Union is a multicultural, multilingual organisation with 1000 staff located in 62 countries. Its headquarters are in Gland, Switzerland. http://www.iucn.org/
The IUCN Red List of Threatened Species
The IUCN Red List is widely recognized as the most comprehensive source of information on the global conservation status of plant and animal species and can be used as a tool for measuring and monitoring changes in the status of biodiversity and our knowledge of the taxa. Red Lists are among the most widely used tools available to conservationists worldwide for focusing attention on species of conservation concern. They are an essential basis to enable management priorities to be targeted and for monitoring the long-term success of management and conservation initiatives. The assessments evaluate the conservation status of individual species, identify threatening processes affecting them and, if necessary, propose recovery objectives for their populations.
The IUCN Groupers and Wrasses Specialist Group (GWSG)
The GWSG was formed in 1998 in response to concerns that a number of larger reef fishes in the grouper and wrasse families are particularly vulnerable to fishing because of their biological characteristics, such as slow reproductive rates and delayed sexual maturity, and needed more attention from specialists to assess their conservation status. The GWSG comprises 35 of the top grouper and wrasse experts from 20 countries. The GWSG, through its membership, is extensively involved in research, management and outreach activities. In addition to the recent workshop, the GWSG has for many years been working for the better management of one of the largest of all reef fish species, the giant Napoleon fish or Humphead wrasse (Cheilinus undulatus), which was listed on CITES (Convention on International Trade in Endangered Species) Appendix II in October 2004. This was a significant listing inasmuch as it was the first commercial food fish to be so-listed. The SG is now working closely with FAO (United Nations Food & Agriculture Organization) and with the Indonesian government (Indonesia is the major exporter of the species) to develop a sustainable management plan for the species. www.http://www.hku.hk/ecology/GroupersWrasses/iucnsg/index.html (Species section)