Featured Research

from universities, journals, and other organizations

Genetic survey of endangered Antarctic blue whales shows surprising diversity

Date:
March 7, 2012
Source:
Oregon State University
Summary:
More than 99 percent of Antarctic blue whales were killed by commercial whalers during the 20th century, but the first circumpolar genetic study of these critically endangered whales has found a surprisingly high level of diversity among the surviving population of some 2,200 individuals. That may bode well for their future recovery.

Antarctic blue whale. A new study, using samples collected during cruises coordinated by the International Whaling Commission, has found a surprisingly high level of genetic diversity among critically endangered Antarctic blue whales.
Credit: Photo by Paul Ensor, with support from Canon New Zealand Community Sponsorship Programme

More than 99 percent of Antarctic blue whales were killed by commercial whalers during the 20th century, but the first circumpolar genetic study of these critically endangered whales has found a surprisingly high level of diversity among the surviving population of some 2,200 individuals.

Related Articles


That, says lead author Angela Sremba of Oregon State University, may bode well for their future recovery.

Results of the study have just been published in the open-access journal, PLoS ONE. As part of the study, the researchers examined 218 biopsy samples collected from living Antarctic blue whales throughout the Southern Ocean from 1990 to 2009, through a project coordinated by the International Whaling Commission.

The genetic survey revealed a "surprisingly high" level of diversity that may help the population slowly rebound from its catastrophic decimation by whalers.

"Fewer than 400 Antarctic blue whales were thought to have survived when this population was protected from commercial hunting in 1966," noted Sremba, who conducted the research as part of her master's degree with the Marine Mammal Institute at OSU's Hatfield Marine Science Center. "But the exploitation period, though intense, was brief in terms of years, so the whales' long lifespans and overlapping generations may have helped retain the diversity."

"In fact," she added, "some of the Antarctic blue whales that survived the genetic bottleneck may still be alive today."

Prior to whaling Antarctic blue whales were thought to number about 250,000 individuals -- a total that dwindled to fewer than 400 animals by 1972 when blue whales were last killed by illegal Soviet whaling. Blue whales are thought to be the largest animals ever to have lived on Earth, said OSU's Scott Baker, associate director of the Marine Mammal Institute and an author on the study -- and the Antarctic blue whales were even larger than their cousins in other oceans.

"These animals are very long-lived -- maybe 70 to 100 years -- and they can grow to a length of more than 100 feet and weigh more than 330,000 pounds," he said. "There is a jawbone in a museum in South Africa that takes up most of the lobby. This is one reason they were so intensively exploited; they were the most valuable whales to hunt."

Despite their history of exploitation, little is known about modern-day movements of Antarctic blue whales, which are considered a separate subspecies -- differing in size and habitat use -- from the smaller "pygmy" blue whales, which live in more temperate regions of the Southern Hemisphere.

Through "microsatellite genotyping," or DNA fingerprinting, the PLoS ONE study was able to track some of the movements of individual Antarctic blue whales.

"We documented one female that traveled from one side of Antarctica to the other -- a minimum distance of more than 6,650 kilometers over a period of four years," said Sremba, who is now continuing her studies as a Ph.D. student in the Department of Fisheries and Wildlife at OSU. "It is the first documentation of individual movements by Antarctic blue whales since the end of the commercial whaling era."

Baker said the long distance movement of a few individuals was "somewhat surprising" in comparison to the evidence for genetic differences between areas of the Southern Ocean. On one hand, it is apparent that individual Antarctic blue whales are capable of traveling enormous distances in search of food.

"On the other hand," Baker said, "there seems to be some fidelity to the same feeding grounds as a result of a calf's early experience with its mother. This 'maternally directed' fidelity to migratory destinations seems to be widespread among great whales."

There is much, however, which scientists still don't know about Antarctic blue whales, Baker pointed out.

"This is a poorly understood species of whales, despite its history of exploitation," Baker said. "Only now are we developing the technology to study such a small number of whales spread across such a vast habitat."

The biopsy samples were collected during more than two decades of research cruises supervised by the International Whaling Commission, and with international scientists joining research vessels from the Japanese Ministry of Fisheries.

Now that their population is slowly recovering, future studies may focus on Antarctic blue whales' migration patterns, and the locations of their breeding and calving grounds.


Story Source:

The above story is based on materials provided by Oregon State University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Angela L. Sremba, Brittany Hancock-Hanser, Trevor A. Branch, Rick L. LeDuc, C. Scott Baker. Circumpolar Diversity and Geographic Differentiation of mtDNA in the Critically Endangered Antarctic Blue Whale (Balaenoptera musculus intermedia). PLoS ONE, 2012; 7 (3): e32579 DOI: 10.1371/journal.pone.0032579

Cite This Page:

Oregon State University. "Genetic survey of endangered Antarctic blue whales shows surprising diversity." ScienceDaily. ScienceDaily, 7 March 2012. <www.sciencedaily.com/releases/2012/03/120307184926.htm>.
Oregon State University. (2012, March 7). Genetic survey of endangered Antarctic blue whales shows surprising diversity. ScienceDaily. Retrieved November 23, 2014 from www.sciencedaily.com/releases/2012/03/120307184926.htm
Oregon State University. "Genetic survey of endangered Antarctic blue whales shows surprising diversity." ScienceDaily. www.sciencedaily.com/releases/2012/03/120307184926.htm (accessed November 23, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Sunday, November 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Anglerfish Rarely Seen In Its Habitat Will Haunt You

Anglerfish Rarely Seen In Its Habitat Will Haunt You

Newsy (Nov. 22, 2014) For the first time Monterey Bay Aquarium recorded a video of the elusive, creepy and rarely seen anglerfish. Video provided by Newsy
Powered by NewsLook.com
Birds Around the World Take Flight

Birds Around the World Take Flight

Reuters - Light News Video Online (Nov. 22, 2014) An imperial eagle equipped with a camera spreads its wings over London. It's just one of the many birds making headlines in this week's "animal roundup". Jillian Kitchener reports. Video provided by Reuters
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. Video provided by Newsy
Powered by NewsLook.com
Raw: Baby Okapi Born at Houston Zoo

Raw: Baby Okapi Born at Houston Zoo

AP (Nov. 20, 2014) The Houston Zoo released video of a male baby okapi. Okapis, also known as the "forest giraffe", are native to the Democratic Republic of the Congo in Central Africa. Video is mute from source. (Nov. 20) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins