Genetic research by the Bronx Zoo-based Wildlife Conservation Society, American Museum of Natural History, and other organizations has revealed that right whales living in the North Pacific Ocean are actually a unique species, according to a study published in the recent issue of the journal Molecular Ecology. Long considered to be another population of northern right whale, a species numbering fewer than 300 individuals in the North Atlantic, right whales of the North Pacific are genetically distinct, scientists say.
"There is very little recent information about the North Pacific right whale, other than sporadic sightings, and the fact that it has been hard-hit by illegal hunting," said WCS researcher Dr. Howard Rosenbaum, the study's lead author. "What is known is that this animal numbers perhaps a few hundred individuals throughout their entire range in the North Pacific and should therefore be a top conservation priority."
In 1997, Rosenbaum and colleagues at WCS and the American Museum of Natural History developed a technique to isolate DNA from the baleen of historical specimens of whales - some of which were over a century old. This procedure allowed researchers to conduct the first genetic analysis of North Pacific right whales. Rosenbaum's team looked at samples from a total of 380 whales, including skin-tissue biopsy samples from recent animals, to support these important findings. The conclusion that the North Pacific right whale is a valid species brings the total number of species to three - adding to the northern right whale in the North Atlantic Ocean and the southern right whale.
Both of those species are currently listed as endangered according to the Convention on International Trade of Endangered Species of Fauna and Flora (CITES). Rosenbaum believes that these recent findings will help guide changes to the federal Endangered Species Act, which currently recognizes just one species of right whale occurring in U.S. waters.
Like other right whale species, the North Pacific right whale reaches about 45 feet in length and weighs as many tons. It is found on both sides of the Pacific Ocean, from the southeastern Bering Sea to the Okhotsk Sea off western Russia. Some estimates put the total population from the western North Pacific in the high hundreds, but the actual population may be much lower. The population in the eastern North Pacific, most likely residing in or migrating through U.S. waters, is suspected to be made up of a small number of individuals. Scientific surveys over the past few years have provided valuable information, including samples for genetic analysis from these populations.
The slow-swimming cetacean was the foundation of early commercial whaling ventures and the target of pelagic whaling fleets and coastal whaling, though the species was reported in decline as early as 1874. By 1937, all right whales became internationally protected. However, wide-scale illegal hunting by Soviet fleets in the 1960's is likely to have devastated populations.
Today, scientists have documented that northern right whales in the Atlantic are experiencing lowered reproductive success, and are threatened by ships that collide with the animals and fishing nets that entangle them. Some of the same threats may be impacting the North Pacific right whale, but virtually no studies exist to evaluate their respective toll on the species.
"There has been a lot of conservation work directed toward the North Atlantic right whale," said Rosenbaum. "And while those efforts should continue and remain of highest priority, the conservation community should also focus attention on the North Pacific species to safeguard remaining populations."
Materials provided by Wildlife Conservation Society. Note: Content may be edited for style and length.
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