WHILE governments and interest groups have been fighting over the future of the world鈥檚 great whales, some smaller cetaceans have been quietly heading towards extinction. Certain species, such as the baiji, or Yangtze River dolphin, may not survive another decade, says a report from the World Conservation Union.
Conservation groups must broaden their focus to include these smaller species, says Randall Reeves, chair of the IUCN Cetacean Specialist group and co-author of the report. For example, anti-whaling organisations have long campaigned against Japan鈥檚 annual 鈥渟cientific harvest鈥� of 400 minke whales. But the International Whaling Commission believes there are at least 260,000 minke in the Southern Ocean, while there may be no more than a few tens of baiji left. 鈥淭he threats to baiji seem much more insidious and intractable than the threats to minke whales,鈥� says Reeves.
鈥淭he small cetaceans that are dying in droves every year in fishing nets lose out in the shadow of the whaling controversy,鈥� he says. Many other whales, dolphins and porpoises are undernourished and less likely to give birth to fat, healthy calves, and the river dolphins鈥� habitat is shrinking rapidly because of the human demand for water.
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The scale of the problem of cetacean by-catches was highlighted in a recent survey of boats fishing off north-west Spain. The survey found unsustainable numbers of common and bottlenose dolphins were being killed accidentally in fishing nets (Biological Conservation, vol 111, p 25).
Although northern right whales and blue whales are endangered, there are signs that commercial hunt bans have allowed some populations of southern right whales, humpbacks, grey whales and blue whales to recover. But the baiji and the vaquita, a porpoise that lives in the Gulf of Mexico, are now classed as critically endangered on the IUCN Red List. New Zealand鈥檚 Maui鈥檚 dolphin and certain populations of the Irrawaddy dolphins of the Mahakam river in Indonesia are also in urgent need of protection, says Reeves.