Scientists have documented the first known migration of blue whales from the coast of California to areas off British Columbia and the Gulf of Alaska since the end of commercial whaling in 1965.
In the scientific journal Marine Mammal Science, researchers from Cascadia Research Collective in Washington state, NOAA's Southwest Fisheries Science Center in California, and Canada's Department of Fisheries and Oceans identified 15 separate cases where blue whales were seen off British Columbia and the Gulf of Alaska. Four of the whales were identified as animals previously observed off the coast of California, suggesting a re-establishment of a historical migration pattern.
Researchers made this identification by comparing photographs of blue whales taken in the north Pacific Ocean since 1997 with a library of nearly two thousand photographs of blue whales off the West Coast. A positive match was determined based on pigmentation patterns in skin color and shape of the dorsal fin.
Blue whales were severely depleted during commercial whaling activities during the early 1900's in the north Pacific and along the West Coast as far south as Baja California. Formerly large populations of blue whales in the north Pacific never rebounded after commercial whaling ended while those animals off southern California have apparently fared much better.
Scientists are still not certain exactly why blue whales are now beginning to migrate from southern California to the north Pacific Ocean although changing ocean conditions may have shifted their primary food source of krill further north.
Blue whales are thought to be the largest animal ever to have existed on earth, reaching lengths of nearly 100 feet. They were nearly hunted to extinction throughout the world and are currently listed as endangered under the U.S. Endangered Species Act and as endangered on the red list of the International Union for the Conservation of Nature
'/>"/>
| Contact: Jim Milbury jim.milbury@noaa.gov 562-980-4006 NOAA National Marine Fisheries Service Source:Eurekalert |
Related biology news :
1. Stanford researchers: Global warming is killing frogs and salamanders in Yellowstone Park
2. Columbia researchers: Growth of CT scan use may lead to significant public health problem
3. Researchers: No faking it, crocodile tears are real
4. Mama whales teach babies where to eat
5. Early whales gave birth on land
6. Older killer whales make the best mothers
7. Early whales gave birth on land, fossil find reveals
8. High numbers of right whales seen in Gulf of Maine
9. UBC researcher reveals humpback whales dining habits -- and costs
10. Unique study shows oil, gas seismic work not affecting Gulf sperm whales
11. Whales and dolphins influence new wind turbine design
 |
| Copyright © 2003-2012 Bio-Medicine. All rights reserved. ABOUT | CONTACT US | DISCLAIMER | PRIVACY POLICY | TERMS AND CONDITIONS |  |