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:7/27/2014)... might have survived the asteroid strike that wiped them ... later in history, scientists say. , A fresh study ... helped palaeontologists to build a new narrative of the ... They found that in the few million years before ... was experiencing environmental upheaval. This included extensive volcanic activity, ...
(Date:7/27/2014)... have shown the potential for global climate change to ... most part, ignored the interactions between increasing temperature and ... to damage crops. , A new study involving researchers ... significant, suggesting that policymakers need to take both warming ... , The study looked in detail at global production ...
(Date:7/25/2014)... the first broad-scale estimate of air pollution removal by ... that trees are saving more than 850 human lives ... symptoms. , While trees, pollution removal equated to an ... the impacts of that improvement are substantial. Researchers valued ... at nearly $7 billion every year in a study ...
Breaking Biology News(10 mins):Dinosaurs fell victim to perfect storm of events, study shows 2Study: Climate change and air pollution will combine to curb food supplies 2Study: Climate change and air pollution will combine to curb food supplies 3First national study finds trees saving lives, reducing respiratory problems 2
(Date:7/28/2014)... new method of building materials using light, developed by ... enable technologies that are often considered the realm of ... , Although cloaked starships won,t be a reality ... developed for constructing materials with building blocks a few ... control the way that light flies through them, and ...
(Date:7/28/2014)... July 28, 2014 “2014 ... Lubricant Industry” is a professional and in-depth ... market. The report introduces Lubricant basic information, ... chain structure and industry overview. This research ... domestic market as well as global industry ...
(Date:7/28/2014)... -- Research and Markets has announced the ... report to their offering. ... covers the designing and engineering of completely new biological ... of natural biological systems that provide improved and desirable ... extreme genetic engineering because it not only alters existing ...
(Date:7/28/2014)...  David Hardison, Ph.D., vice president of health ... been elected chairman of the board for the ... to establish common protocols around the use of ... electronic health records. Hardison will ... organizations across the research and health care arena ...
Breaking Biology Technology:Building 'invisible' materials with light 2Lubricant Market & Adhesion Promoter Industry (Globa, China) Analysis Now Available at DeepResearchReports.com 2Lubricant Market & Adhesion Promoter Industry (Globa, China) Analysis Now Available at DeepResearchReports.com 3Lubricant Market & Adhesion Promoter Industry (Globa, China) Analysis Now Available at DeepResearchReports.com 4Global Synthetic Biology Market 2014-2018 2ConvergeHEALTH by Deloitte's David Hardison Named Chairman of the Clinical Data Interchange Standards Consortium 2ConvergeHEALTH by Deloitte's David Hardison Named Chairman of the Clinical Data Interchange Standards Consortium 3
Cached News: