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:


(Date:2/7/2017)... , February 7, 2017 ... Global Solutions Corporation [OTC: IDGS], ("Ipsidy" or the "Company") ... electronic transaction processing services, is pleased to announce the ... Company. Effective January 31, 2017, Philip ... of Directors, CEO and President.  An experienced payment industry ...
(Date:2/2/2017)...   TapImmune, Inc. (NASDAQ: ... the development of innovative peptide and gene-based immunotherapeutics ... metastatic disease, announced today it has successfully completed ... second clinical lot of TPIV 200, the company,s ... manufactured vaccine product will be used to supply ...
(Date:1/31/2017)... CAMBRIDGE, Mass. , Jan. 31, 2017 /PRNewswire-USNewswire/ ... develop novel therapies for the treatment of bacterial ... generation set of antibacterial candidates from Pro Bono ... the increased prevalence of multi-drug resistant forms of ... by Cantab Anti Infectives Ltd, a PBB group ...
Breaking Biology News(10 mins):
(Date:2/23/2017)... ... 23, 2017 , ... Brain Sentinel, Inc. has received US ... System, the Brain Sentinel® Seizure Monitoring and Alerting System. The adjunctive seizure monitoring ... of rest. A lightweight, non-invasive monitor is placed on the belly of the ...
(Date:2/23/2017)... LOS ANGELES , Feb. 23, 2017  Capricor Therapeutics, ... cardiac and other medical conditions, today announced that Linda Marbán, ... at two upcoming investor conferences: Cowen ... 2017 at 10:00 am ET Boston, MA ... 14, 2017 at 9:00 am PT (12:00 pm ET) ...
(Date:2/22/2017)... ... February 22, 2017 , ... Kernel , ... Research Systems, LLC (KRS) clinical development program. KRS is a neurotechnology spin-out ... research and clinical applications. The terms of the transaction were not disclosed. ...
(Date:2/22/2017)... ... February 22, 2017 , ... ProMIS ... precision treatments for neurodegenerative diseases, today announced it has issued a scientific white ... is one of a series of commentaries from ProMIS’s scientific team offering insight ...
Breaking Biology Technology:
Cached News: