The humphead wrasse - A conservation challenge taken up by SSC Specialist Group

By Yvonne Sadovy, Chair, Grouper & Wrasse Specialist Group, An extract from Species - the SSC newsletter, issue 36

Humphread wrasse (Cheilinus undulatus), a highly prized food fish. Over-fishing is having a serious impact on many populations.

The humphead, or Napoleon, wrasse, Cheilinus undulatus, is one of the largest of all reef fishes and the biggest of the wrasse family, the Labridae. It can reach well over two meters in length and 200 kilograms in weight - an elephant of coral reefs. This species is considered a gourmet food fish and is appreciated for the fine taste and texture of its flesh. In many areas of the Pacific, it is of considerable local traditional significance, long used for special ceremonies in Fiji, Palau, and elsewhere. More recently, it has become a small, but significant component of the international luxury trade in live reef fish which has expanded rapidly within the last decade in developed areas of southeast Asia. In restaurants and seafood markets in Hong Kong, for example, this species has retailed for as much as US$100/kg and it is also widely on sale in Taiwan, Singapore and southern China. It is one of the most highly valued species in the trade.

Like many large reef fishes, the humphead wrasse does not appear to be particularly common. Its lifespan of at least a couple of decades, and low replacement rates, mean that it is unlikely to recover readily from anything other than the low levels of local fishing effort to which it was exposed in the past. It is not an easy species to catch, but with the advent of night spearing (when animals are readily taken from their sleeping holes) and the growing demand for exports in the international live reef fish trade, there is now considerable concern that this widespread, but uncommon, species is being threatened. It was included in the 1996 IUCN Red List as vulnerable. Concerns for its status have already led to protection in parts of Australia and the Philippines, and in the Maldives and Palau. One diving fraternity is so concerned about this species (a favourite with divers) it has set up its own monitoring network to report on known individuals (large adults are reasonably site-faithful) and lobby for protection.

Several aspects of the life history, fishery and trade in this species make conservation efforts particularly challenging, and, being a marine fish, population estimates for species assessments are fraught with difficulties. Despite considerable concern for its status in some areas, its large size, wide-ranging behavior and shy nature make it very difficult to study in the field, or to survey using underwater visual census techniques. On the other hand, its low volume in most local fisheries means that it is rarely monitored.

On the demand side, we know that adults are increasingly uncommon and most fish on sale in Hong Kong, the centre of international trade, are now juveniles. Little is known of the biology of this species and its likely status has been assembled from numerous anecdotal accounts from fishers, divers, biologists throughout the Indo-Pacific in both source and destination countries. The picture that is emerging from these sources is a consistent and disturbing one of declining numbers wherever an export trade develops. Because so little information is recorded, there is little realization of the breadth of the problem with this species.

Faced with a general lack of understanding of the humphead wrasse but considerable concern, our Specialist Group is working on a synopsis of data and awareness campaigns especially in countries which are developing, or likely to develop an export trade for live reef fish. A small grant recently awarded from the Chicago Zoological Society will support an education programme aimed at highlighting the status and vulnerability of this species in much of its range and the concerns over the impacts of international trade. We aim to promote data collection within local fisheries and protection from export, while encouraging biologists to develop research projects to improve the means of surveying this, and similar, marine fishes. Studies are also needed on its biology. In the demand center of Hong Kong, campaigns of consumer education are being conducted and our Specialist Group works together with the government and local non-governmental organizations to raise awareness of the status of this species among live reef fish traders and to improve the collection of import data.

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