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With Humpback Whales’ Baby Boom, Scientists May Revoke Endangered Species Status

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Known for their acrobatics, breaching humpbacks are impressive. Wanetta Ayers/Wikimedia Commons.

Known for their acrobatics, breaching humpbacks launch out of the water. Scientists speculate this behavior may be a form of communication, dislodges external parasites or is just for fun. (Wanetta Ayers/Wikimedia Commons)

The boat slowed as we watched a 40-ton whale launch itself skyward and crash back into the sea. It’s primetime for migrating humpback whales in the North Pacific breeding ground as they frolic, mate and raise their young while living off their blubber. The good news is that humpback populations have rebounded significantly since they were first protected as an endangered species in 1966. From an estimated low of about 5,000 animals worldwide, humpbacks in the North Pacific are now estimated at near their pre-whaling population of 22,000.

New research from a December 2013 press release states scientists examined “nearly 2,200 tissue biopsy samples collected from humpback whales in 10 feeding regions and eight winter breeding regions during a three-year international study, known as SPLASH (Structure of Populations, Levels of Abundance and Status of Humpbacks). They used sequences of maternally inherited mitochondrial DNA and ‘microsatellite genotypes,’ or DNA profiles, to both describe the genetic differences and outline migratory connections between both breeding and feeding grounds.”

Humpback calves are born in the warm waters of Mexico and Hawaii, staying with their mothers for one year. Dave Glickman/Wikimedia Commons

Humpback calves are born in warm waters then migrate after a few months, staying with their mothers for one year. (Dave Glickman/Wikimedia Commons)

“Though humpback whales are found in all oceans of the world, the North Pacific humpback whales should probably be considered a sub-species at an ocean-basin level – based on genetic isolation of these populations on an evolutionary time scale,” said Scott Baker, associate director of the Marine Mammal Institute at Oregon State University’s Hatfield Marine Science Center and lead author on the paper.

“Within this North Pacific sub-species, however, our results support the recognition of multiple distinct populations,” Baker added. “They differ based on geographic distribution and with genetic differentiations as well, and they have strong fidelity to their own breeding and feeding areas.”

The study identifies five distinct populations of humpback whales in the North Pacific based on their breeding grounds: Okinawa and the Philippines; a second West Pacific population with unknown breeding grounds; Hawaii, Mexico and Central America.

Male humpbacks sing intricate songs to attract a mate in their breeding grounds. Dr. Louis M.  Herman/Wikimedia Commons

Male humpbacks sing underwater to attract a mate in their breeding grounds. (Dr. Louis M.
Herman/Wikimedia Commons)

These new population distinctions could provide vital information in NOAAs current one-year study to determine whether humpback whales in the North Pacific should be taken off of the Endangered Species list.  The petition to delist humpbacks was brought forward on April 17, 2013, by the Hawai’i Fishermen’s Alliance for Conservation and Tradition, Inc.  In February 2014. the Alaska Department of Fish and Game submitted their own petition to delist the humpbacks.

For more about humpbacks and our own California gray whales, check out my “Gigantic Journeys” blog.

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Category: Biology

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About the Author ()

Sharol Nelson-Embry is the Supervising Naturalist at the Crab Cove Visitor Center & Aquarium on San Francisco Bay in Alameda. Crab Cove is part of the East Bay Regional Park District, one of the largest and oldest regional park agencies in the nation. She graduated from Cal Poly, San Luis Obispo with a degree in Natural Resources Management and an epiphany that connecting kids with nature was her destiny. She's been rooted in the Bay Area since 1991 after working at nature centers and outdoor science schools around our fair state. She loves the great variety of habitats stretching from the Bay shoreline to the redwoods, lakes, and hills. Sharol enjoys connecting people to nature with articles in local newspapers and online forums. Read her previous contributions to QUEST, a project dedicated to exploring the Science of Sustainability.