墨西哥及紐西蘭的海豚瀕臨滅絕

Extinction is imminent for two marine mammal species unless their habitat is immediately cleared of gillnets, the International Whaling Commission was warned last week at its meeting in Panama City.

The IWC's Scientific Committee told hundreds of delegates from the 89 IWC member governments that Mexico's vaquita porpoise and the world's rarest marine cetacean, New Zealand's Maui's dolphin, are both Critically Endangered and at immediate risk of extinction.

Both marine mammals are threatened by accidental bycatch in gillnet fisheries. A total ban on the use of gillnets in the entire ranges of both populations is needed to secure their survival, according to the Scientific Committee's report.

IWC member governments urged Mexico and New Zealand to take all possible measures immediately to save these animals from extinction.

"It's time for diplomatic niceties and step-wise strategies to take a back seat to immediate, concrete action with no compromise," said Michael Stachowitsch, delegate of Austria to the IWC.

The vaquita porpoise, Phocoena sinus, clings to existence in the Upper Gulf of California, Mexico. There were only about 220 animals in 2008 and the population continues to decline. It is estimated that at least 30-85 individuals are taken incidentally in fishing nets each year. Other possible threats to this species include environmental pollution, habitat degradation, and inbreeding due to low population numbers, according to the U.S. National Oceanic and Atmospheric Administration.

The IWC's scientific report strongly recommends that, if extinction is to be avoided, all gillnets should be removed from the upper Gulf of California immediately.

A number of countries echoed the Scientific Committee's concern and while recognizing Mexico's efforts to date, urged action as soon as possible. "Mexico understood and recognized this concern," said the IWC in a summary of discussions.

Mexico has established the International Committee for the Recovery of the Vaquita as well as a bio-reserve in the upper portion of the Gulf of California.

"Mexico has the power to save this unique species by banning all gillnets in vaquita habitat," said Aimee Leslie, WWF's marine turtle and cetacean manager.

Incidental capture in fishing operations is the biggest threat to cetacean species today, said Leslie. "It is estimated that more than 300,000 whales, dolphins and porpoises die each year from entanglement in many types of fishing gear, which is an average of one cetacean killed by bycatch every two minutes."

The IWC Scientific Committee urged New Zealand to take immediate steps to arrest the decline of its only native dolphins, pointing out that current protection measures are inadequate in terms of the area and the fishing methods they cover.

Since the introduction of nylon filament nets in the 1970s, Hector's dolphin numbers have dropped from 30,000 to around 7,000. The situation for Maui's dolphins, Cephalorhynchus hectori maui, a subspecies of Hector's dolphins, is even worse. More than 94 percent are already lost and Maui's dolphins are now confined to very small remnant population on the west coast of New Zealand's North Island.

With just 55 survivors older than one year, fewer than 20 breeding females, and an annual decline of around three percent, Maui's dolphins are facing imminent extinction.

"Hector's and Maui's dolphins inhabit coastal waters up to a depth of 100 meters," says Dr. Barbara Maas, of the German conservation group NABU International, which released a report highlighting the urgent need to protect this species at the IWC.

"The New Zealand government has been exposed to fierce pressure from fishing interests, which strongly oppose any measures to protect the dolphins. We are therefore delighted that the IWC has confirmed what scientists and conservationists have been calling all along: a ban on gillnets and trawling in waters up to 100 meters depth," said Maas.

New Zealand informed the commission that it is extending the existing protected area on the Taranaki coast in order to improve the situation.

Yet the New Zealand delegation failed to mention that these measures are temporary, they do not include trawl fishing and do not apply to most of the dolphins' habitat.

The New Zealand conservation group Forest & Bird says the government's move still does not adequately protect Maui's dolphins from extinction because other significant areas remain completely unprotected.

Forest & Bird Advocacy Manager Kevin Hackwell said, "The set net ban needs to be extended to all regions where these nationally-critical Maui's dolphins are found. That includes all harbors and offshore to the 100 meter depth contour."

"It's imperative we remove the threat by adopting a ban that completely covers their habitat," said Hackwell. "We need stronger measures to be implemented now, not at the end of the year after the Threat Management Plan has been reviewed."

Hackwell says requiring observers on commercial fishing vessels will do little to actually stop dolphins from dying in set nets. "It's going to force fishers to put observers on their boats, which is good. It's a step in the right direction. But it won't stop dolphins being killed. It will just mean that we'll know how many we've caught."

Research considered by the IWC's Scientific Committee shows that protected areas are too small to be effective, and progress in extending gillnet and trawl net free areas has been too slow to achieve recovery as part of New Zealand's national and international obligations. .

The Scientific Committee's priority topic this year was a review of the 10 beaked whale species found in the North Pacific and northern Indian Ocean. These populations are not well understood and the scientific body stressed their vulnerability to military sonar and to seismic surveys for oil and gas and the problem of bycatch in fishing nets.

The Committee also noted bycatch in fishing gear and other threats affecting harbor porpoise populations in European waters of the Belt Sea and the inner Baltic. It urged development of effective monitoring and mitigation measures.

It expressed concern over high bycatches in fishing gear of a population of Franciscana dolphins, pontoporia blainvillei, in Brazil and endorsed a national recovery plan. One of the world's smallest dolphins, the Franciscana is the only one of the four river dolphin species living in the marine environment and the sole member of its family.

Longstanding concerns exist over the status of river dolphins. The Scientific Committee this year had additional concerns over intentional killing for bait in Brazil of two Amazon species, the botu and the tucuxi, in addition to other threats they face. It made a number of recommendations and Brazil and other range states indicated their willingness to act on these.

The Scientific Committee was pleased to hear of conservation efforts for the Indus River dolphins in Pakistan and the Mekong River population of Irrawaddy dolphins in Cambodia.

The only known loss of a mammal species from human causes was the Chinese baiji, or Yangtze river dolphin, which was declared functionally extinct by the IWC in 2006.