The Humphead Wrasse, Cheilinus undulates The Humphead wrasse, Cheilinus undulates, is the largest member of the family Labridae and widely distributed across the reefs of the Indo-Pacific. It is found from the Red Sea and African coast, across the Indian Ocean and much of the Pacific, north to southern Japan and the coast of southern China, and south to New Caledonia. In English it is mostly commonly referred to as the Humphead, Maori or Napoleon wrasse. Fishery management The species has a high economic value and is a special favorite of both the live reef food fish trade and with recreational divers. The Humphead wrasse is vulnerable to fishing due to its long life and late sexual maturation (which occurs at approximately 50 cm total length and 5 years of age).

This means that its life history is one that involves slow replacement (and hence slow recovery from fishing) rates. Because of its high value as food, it is heavily sought by fishers and traders. As part of the live food fish market, its value is likely to increase with rarity, so fishers will continue to fish this species even as its numbers decline. Humphead wrasse fisheries are mostly un managed and, even if managed 'on paper', there is usually little management or monitoring of Humphead wrasse in local fisheries.

Monitoring is needed, both of local capture and of exports. Without proper management and monitoring, it is impossible to know whether current capture rates are sustainable or to establish safe quotas capture. On the other hand, its value to diving tourism will remain high if it is protected and remains alive in the wild. Live Reef Food Fish Trade While there is some capture for local use, particularly in the western and central Pacific, the Humphead wrasse is primarily taken for export as part of the valuable live reef food fish trade which is centred in SE Asia. All fish in this trade are wild-caught since commercial level hatchery propagation of this species is not yet possible. The major importing countries are China (especially Hong Kong), Taiwan and Singapore.

Fish are exported especially from Indonesia, Malaysia, the Philippines and from some western Pacific Islands. Hong Kong is the biggest consumer / transshipment centre for the live seafood market, including for the Humphead wrasse. Hong Kong re-exports significant but undocumented volumes of Humphead wrasse into mainland, particularly southern, China, according to traders and to market surveys. The live reef fish industry in Hong Kong is worth over US$500 million, with Hong Kong consumers willing to pay up to US$175 / kg for the smaller individuals. The most preferred trade, or market, size for this fish in the export trade as food is 'plate-sized' - between about 30-60 cm (mainly 30-45 cm) total length. Plate-sized fish are typically sexually immature since sexual maturity occurs at about 50 cm.

This means that large numbers of sexually immature fish are removed from the wild for the live reef food fish trade. The relatively large sizes of these juvenile fish mean that they would very likely survive to reproduce in the wild, if not removed. Capture Methods The Humphead wrasse is caught in different ways according to its size, whether it is needed alive or dead and depending on local traditions. Smaller individuals may be attracted by bait of cut or living fish and crabs on hook and line or fish traps. Adult Humphead wrasse are very vulnerable to night-fishing, especially if SCUBA is used, since they are easily taken from their caves while they sleep. The Humphead wrasse spawns in aggregations that can easily be target ted by fishers and hence are particularly vulnerable to overfishing at the times and places at which reproduction occurs.

It has been well-documented that spawning aggregations in several other reef fish species are particularly vulnerable to being over fished. Recently, cyanide has been used to extract the fish from among corals if fish are to be maintained alive. Cyanide seems to be particularly widely used where this species was not formerly part of a traditional fishery and the poison is often introduced or supplied by foreign traders in live reef fish. Cyanide is a poison and is known to kill living coral. The Humphead wrasse, as with many other reef fish and invertebrate species, depend on healthy coral reefs for shelter. Loss of this habitat could severely affect reef communities, and their habitats.

The Humphead wrasse can also change sex from female to male. This makes the species susceptible to size-selective ( = sex selective) fishing that could lead to imbalances in the reproductive sex ratio and reduce reproductive potential. Conservation Efforts Several aspects of the life history, fishery and trade for this species make conservation efforts challenging, and, being a marine fish, population estimates for species assessments are difficult to attain. 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. In terms of demand, 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 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. 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. References Economist Newspaper Ltd, 1996. Cyanide sauce: Hong Kong fishermen's practice of spraying cyanide on fish underwater is threatening to kill off the fish population of the Pacific reefs. The Economist, v 339 n 7965 p 35 (2) Barber, C.

V. and V. R Pratt, 1998. Poison and profits: cyanide fishing in the Indo-Pacific. Environment, v 40 n 8 p 4 (13) Ride, Anouk, 2000.

Dead in the water: Anouk Ride examines the poisonous effects of the billion-dollar trade in tropical fish. New Internationalist, i 325 p 27 Hinrichs en, Don, 1997. Coral reefs in crisis: Solutions to problems plaguing coral reefs all over the world are provided. Problems such as pollution, cyanide and dynamite fishing, coastal development can be eliminated through coral reef management programs. Bio Science, v 47 n 9 p 554 (5) Sado vy, Y. , the IUCN Specialist Group on Groupers and Wrasses.

2002. Statement of Concern: The Humphead Wrasse is a Threatened Reef Fish. web.