วันศุกร์ที่ 1 พฤศจิกายน พ.ศ. 2556

‘Astonishing’ North Pacific right whale sighting is only the second in 62 years off British Columbia

Last previous sighting was a mammal killed by whalers in 1951; it's the most endangered whale species on earth

North Pacific right whale spotted last week off British Columbia. Photo by John Ford
North Pacific right whale spotted last week off British Columbia. Photo by John Ford
A North Pacific right whale has been spotted off British Columbia for the second time since June, which is remarkable considering that the last previous sighting in the region was in 1951.
These robust baleen whales were hunted mercilessly during the commercial whaling era and are critically endangered. The Center for Biological Diversity categorizes North Pacific right whales (Eubalaena japonica) as the most endangered whale species on earth.
Their estimated population is less than 50 and scientists have photo-identified fewer than 30 individuals. British Columbia waters are their historic territory, which is why it’s so exciting to scientists to have documented the first two sightings in the region in 62 years.
There’s a sub-population of perhaps 200 right whales that summers in the western Pacific off Japan and north of Japan. It’s not known if the two populations mix so the two populations are regarded as distinct groups. Even combined, it’s significantly smaller than the critically endangered population of 400-plus North Atlantic right whales.
Drawing of a North Pacific right whale is courtesy of Wikipedia, via NOAA
Drawing of a North Pacific right whale is courtesy of Wikipedia, via NOAA
The latest B.C. sighting was made October 25 near the entrance of Juan de Fuca Strait near Victoria, by the operator of a water taxi service. It was confirmed the next day by John Ford of thePacific Biological Station in Nanaimo, B.C.
The other recent sighting, of a different animal, was on June 9, 2013, by a biologist aboard a Canadian Coast Guard boat west of the Queen Charlotte Islands.
Since 1951, there have been a handful of sightings off the West Coast of the United States, but because the population is so tiny, all sightings are considered extraordinary.
“It’s exciting, kind of astonishing, really, to have two different animals sighted four months apart on our coast when there haven’t been any confirmed sightings for the last 62 years,” Ford told theVancouver Sun on Thursday. “We were uncertain whether the species still occurred in Canadian waters and this clearly shows that they do.”
The last previous right whale sighting off B.C., in 1951, was an animal killed by whalers.
Commercial whaling for right whales was banned as a result of international treaties in 1935, but an illegal Russian whaling effort in the 1960s harvested 529 right whales in the Bering Sea and Gulf of Alaska.
“This is probably why they’ve failed to recover,” Ford said.
The right whale spotted last week, which measured about 55 feet, was about 20 feet larger than the whale spotted in June. Ford noticed scarring that looked to have been caused by entanglement. Right whales, which spend lots of time at the surface, are vulnerable to boat strikes and fishing nets.
Scientists are hoping that the use of hydrophones off the British Columbia coast will pick up vocalizations of other right whales, helping to pinpoint their location.
Ford said it was possible that this latest right whale was migrating south, but added: “We really don’t know much about them.”
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