HOME >> BIOLOGY >> NEWS
USGS Finds Sea Otters At Risk From Killer Whales In A Changing Ocean

Because of a lack of Steller sea lions and harbor seals, large numbers of sea otters are being eaten by hungry killer whales in western Alaska waters, according to findings in the October 16 issue of the journal Science. In "Killer Whale Predation on Sea Otters Links Oceanic and Nearshore Ecosystems,"a U.S. Geological Survey biologist and his colleagues at the University of California, Santa Cruz, reported on sharp reductions in sea otter numbers in the North Pacific rim.

"We estimate that between 40,000 and 45,000 sea otters have died since 1990 from killer whale predation in roughly 3,300 kilometers of shoreline," said Jim Estes, a biologist at the Western Ecological Research Center. "This unusual behavior of killer whales toward sea otters ultimately raises questions about the health of our oceans."

In a chain of events possibly initiated by overfishing, said Estes, some killer whales have shifted from ocean feeding to coastal. Their usual diet is Steller sea lions and harbor seals, but populations of these marine mammals recently declined in the North Pacific. While no one knows for certain why these populations crashed, it is believed to be linked to a shift in abundance and kinds of food fish, making food a problem for fish-eating species. Estes said other researchers have reported the fish change possibly resulted from a combination of three factors -- expanding fisheries, increases in ocean temperature, and a depletion of large whales.

After ranging into coastal waters, the killer whales found a substitute prey in sea otters. Fewer sea otters, said Estes, allowed sea urchins to increase in numbers and strip coastal kelp forests. Estes and his colleagues are concerned about how events occurring far out to sea are profoundly affecting shorelife. This dramatic change in how ocean and coastal systems are being linked may affect numerous marine and coastal species, the authors concluded.

The researchers calculated that a killer whale on
'"/>

Contact: Catherine Haecker
catherine_haecker@usgs.gov
703-648-4283
United States Geological Survey
15-Oct-1998


Page: 1 2 3 4

Related biology news :

1. Very-Low-Fat Diet May Compromise Immune Function, Increase Infection Risk In Trained Runners, UB Study Finds
2. USGS Finds Palila Population Remaining Stable
3. Breast Milk Of Women Who Eat Lake Ontario Fish Contains High Levels Of PCBs, UB Study Finds
4. UB Study Finds No Relationship Between Male Consumption Of Lake Ontario Fish And Conception Delay
5. Botanical Products Act Like Estrogen In Animals, Finds University Of Pittsburgh Team
6. Study Of Childrens Fillings Finds No Mercury Exposure
7. USGS Finds That Mysterious Arkansas Bald Eagle Disease Has Spread To Ducks In Eastern States
8. Study Finds Choline Deficiency Harms Memory Center In Mammals Brains
9. AIDS Virus May Evolve Differently In Cerebrospinal Fluid Compared With Blood In Some Patients, UCSF/Gladstone Research Finds
10. Nationwide Study Finds HIV-Positive Women Are At High Risk For Cervical Human Papillomavirus Infection
11. Study Finds Protein Clues To Early Embryo Development

Post Your Comments:
*Name:
*Comment:
*Email:
TAG: USGS Finds Sea Otters Risk From Killer Whales Changing Ocean

(Date:8/21/2014)... Nxt-ID, Inc. (OTCQB: NXTD), a biometric authentication ... today that its shares of common stock and the ... its proposed underwritten public offering of common stock and ... Capital Market, subject to closing of its proposed underwritten ... will trade under the symbol "NXTD" and "NXTDW," respectively. ...
(Date:8/21/2014)... Bacteria growing in near darkness use a previously unknown ... a research team led by a Penn State University ... further research aimed at improving plant growth, harvesting energy ... now occurring on Lake Erie and other lakes worldwide. ... the Science Express edition of the journal ...
(Date:8/21/2014)... might seem easy to ignore, but they are the ... depend upon. Humans are increasingly dependent on algae, too, ... and sink it to the bottom of the ocean. ... laboratory experiments, researchers have evidence showing that viruses infecting ... algae,s blooms, even when all else stays essentially the ...
Breaking Biology News(10 mins):Nxt-ID Approved for NASDAQ Capital Market Listing 2Nxt-ID Approved for NASDAQ Capital Market Listing 3Hot-spring bacteria reveal ability to use far-red light for photosynthesis 2Hot-spring bacteria reveal ability to use far-red light for photosynthesis 3Viruses take down massive algal blooms, with big implications for climate 2
(Date:8/21/2014)... Hershey, PA & Rockville, MD (PRWEB) August 21, 2014 ... Inc. (ITI) is making progress in its development ... allergy to Japanese red cedar pollen. Phase IC studies ... to a real solution to hay fever. , The ... in over 35 million people in Japan. Mountain Cedar ...
(Date:8/21/2014)... Institute for Molecular Medicine Finland (FIMM), University of ... novel "man and machine" decision support system for ... described in PLOS One scientific journal ... computer vision algorithms similar to those used in ... the diagnostically most relevant areas. Tablet computers can ...
(Date:8/21/2014)... An international research team including DESY scientists has observed ... The team reports in the journal Science ... lattices inside the nanodroplets. It is the first time ... in larger samples of what is known as superfluid ... exceeded our best expectations," says Andrey Vilesov of the ...
(Date:8/21/2014)... 2014 Deep Research Report ... professional and in-depth research report on the ... Seaweed Fertilizer information, including Seaweed Fertilizer definition, ... well as industry overview. This research covers ... as well as global industry analysis covering ...
Breaking Biology Technology:Relief for Allergy Sufferers Finally in Sight: Immunomic Therapeutics Closes in on Treatment for Hay Fever in Japan, U.S. 2Relief for Allergy Sufferers Finally in Sight: Immunomic Therapeutics Closes in on Treatment for Hay Fever in Japan, U.S. 3Relief for Allergy Sufferers Finally in Sight: Immunomic Therapeutics Closes in on Treatment for Hay Fever in Japan, U.S. 4A novel 'man and machine' decision support system makes malaria diagnostics more effective 2Scientists observe quantum vortices in cold helium droplets 2Internationals Seaweed Fertilizer Industry 2014 Development Trend Analysis in New Research Study at DeepResearchReports.com 2Internationals Seaweed Fertilizer Industry 2014 Development Trend Analysis in New Research Study at DeepResearchReports.com 3
Cached News: