The International Trade in Seahorses

10 June 1996Vincent, A.C.J.

The rapidly growing trade in seahorses Hippocampus spp. for medicines, aquarium pets, and curios has not hitherto been investigated. This report synthesises findings about the exploitation of seahorses and considers actual and possible effects on wild populations. Its goal is to promote conservation and management initiatives to ensure the survival of seahorse populations, while recognising the needs of human communities that depend on them. Material comes from the author’s extensive field surveys and interviews in Asia, a few published Customs records (notably from Taiwan), and observations by biologists, fishers, traders, and officials around the world. Seahorse taxonomy and geographic ranges remain confused but there are probably 35 species of seahorses, most of which are exploited.

The majority of seahorses go to traditional Chinese medicine (TCM) and its derivatives (e.g., Japanese and Korean traditional medicines) which have a large global constituency. Treatments including seahorses are believed to benefit a range of conditions, including respiratory disorders such as asthma, sexual dysfunctions such as impotence, and general lethargy and pain.

China’s economic growth since the mid-1980s is probably the principal agent in a surge in demand for seahorses; TCM traders in China and TCM suppliers elsewhere report notable increases in Chinese consumption (up to 10-fold in 10 years). In response – and in part because other marine resources are declining – subsistence and small-scale fishers in Asia target seahorses and many obtain the majority of their annual income from these fishes. Shrimp trawl boats and other fishers add their incidental by-catch to the total harvest of seahorses. The trade involves many fishers and consumers, each of whom catches or buys relatively few seahorses. Export routes are often through unofficial channels, such as personal luggage on commercial flights.

At least 32 nations around the world are involved in trading seahorses, from Ecuador, to Italy, to the USA. The largest known net importers are those nations with many Chinese: China, Hong Kong, Taiwan. The largest known exporters are India, the Philippines, Thailand and Vietnam.

Information obtained during interviews, in combination with the few published Customs statistics available, suggest that annual consumption just within Asian nations may amount to 45t of dried seahorses annually (about 16 million individuals). The largest users appear to be China (an initial estimate of 20t), Taiwan (11.2t recorded imports) and Hong Kong (around 10t). Totals and rankings, however, should be interpreted with great caution because data are still tentative and because it was not possible to investigate other nations expected to be large consumers (e.g., Japan, Korea, Malaysia, and Singapore).

Total global consumption of seahorses will be much greater because domestic consumption cannot yet be calculated for most countries, because many nations outside Asia also absorb dried seahorses for medicines (including TCM) and curios, and because the aquarium trade probably absorbs hundreds of thousands of live seahorses, most for sale in North America, Europe, Japan or Taiwan.

Extracting seahorses at current rates appears to be having a serious effect on their populations. The impact of removing millions of seahorses can only be assessed indirectly because global seahorse numbers are unknown, taxonomic identities are unclear, geographic ranges are undefined, and fisheries undocumented. Nonetheless, most participants in established seahorse fisheries reported that catches were dwindling markedly. Indeed, fishers’ reports and preliminary research indicate that seahorse numbers in sample populations from five countries could each have declined by even 50% over the past five years. Large seahorses are considered increasingly rare and even less-desirable seahorses, such as juveniles are now accepted for TCM, aquarium fishes and curios.

Seahorse biology is such that populations will be particularly susceptible to over-fishing: (a) pregnant seahorses must survive if the young are to survive; (b) lengthy parental care combined with small brood size limits reproductive rate; (c) strict monogamy means that social structure is easily disrupted; (d) sparse distribution means that lost partners are not quickly replaced; (e) typically low rates of adult mortality mean that fishing exerts a relatively substantial selective pressure; and (f) low mobility and small home ranges restrict recolonization of depicted areas. Key parameters such as growth rates, longevity and juvenile dispersal remain unstudied.

Demand for seahorses far exceeds supply, according to almost all those interviewed. As an example, one TCM dealer in China sought to buy one tonne of seahorses (perhaps 260 000 animals) from the author immediately, stating he could not obtain that amount elsewhere. Proprietary (patent) remedies are a big growth industry in TCM, with perhaps 30% of seahorses in China now being used for general formulations. Increasing demand, combined with the artisanal nature of the fishery and the paucity of other livelihood options for many seahorse collectors, means that the seahorse trade can be expected to persist even as seahorse numbers decline.

Available evidence indicates that consumption of seahorses should be reduced if long-term persistence of seahorse populations is to be assured. Conservation and management of seahorses would benefit from a series of integrated measures. These include: (a) promoting much-needed biological, taxonomic and trade research; (b) monitoring seahorse populations, imports and exports (c) enacting national and international conservation measures; (d) working cooperatively with TCM communities to reduce demand for seahorses by promoting alternative treatments within TCM; (e) cautioning against the purchase of seahorses as aquarium fishes-they do very badly in captivity; and (f) developing community-based fisheries management and aquaculture projects in seahorse extraction areas. Recent small-scale seahorse conservation initiatives in the Philippines and Vietnam are experiencing initial success.

This report focuses on the effects of direct fishing pressure on seahorses but conservation of their highly productive and highly vulnerable seagrass, mangrove, and coral reef habitats should also be a priority if long term preservation of seahorse populations is to be a realistic objective. Seahorses could serve as popular flagship species around which to rally support for general concerns in marine conservation, including habitat loss and declining fish populations.

Seahorses represent a hitherto unexplored genre of fisheries, those intended primarily for medicine rather than food. Conservation schemes devised for seahorses may be applicable to some of the many other fish species employed in TCM.