Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Elephant seal pups suffer from ocean warming

18.04.2005


Ocean warming has a negative impact on the condition of elephant seals, reveals a study published in the Open Access journal BMC Biology. High ocean temperatures observed from 1975 to the late 1990s are correlated with a 28% decrease in the weight of elephant seal pups. Elephant seals are shown to be sensitive to ocean temperature changes associated with both long-term 25-year cycles and short-term 3-4 year cycles such as those caused by El Niño.

Sea lions and fur seals that feed near their rookeries at the surface of the ocean are known to be very sensitive to water temperature changes, as an increase in water temperature usually causes their prey to migrate to cooler areas, depleting local food resources and resulting in pup starvation. Elephant seals, which feed in deep waters, were previously thought to be better buffered against ocean temperature changes than other sea mammals.

A study by Dr Burney Le Boeuf and Dr David Crocker from the University of California in Santa Cruz, shows that as waters get warmer the average weight of an elephant seal pup decreases. Weaning weights are a direct indicator of food availability to mother seals during their pregnancy. Because their prey has migrated to colder waters, female seals have to swim further and spend more time searching for food. As a result, they gain less body mass while pregnant and have fewer reserves to draw on during nursing. Nursing pups get all nourishment from their mothers; changes in ocean temperature therefore directly affect the weight, and the survival rate, of the pups.

To assess the impact of temperature changes on food availability to elephant seals, Le Boeuf and Crocker monitored the weight of 2750 elephant seal pups over a period of 29 years, from 1975 to 2004. During this time the ocean temperature increased to the highest on record in 1997-98, after the most intense El Niños of the century in 1982-83 and 1997-98, before cooling again in 2000.The pups, from a rookery located in central California, were weighed within 10 days of weaning.

Le Boeuf and Crocker’s results show that the pups’ mean weaning weight declined from 146 kg in 1976 to 115 kg in 1999. This coincided with an increase in mothers’ foraging time of about 36% (as well as a decrease in mass gained). After 1999, however, the declining trend abruptly stopped and the weaning weight of the pups increased to eventually reach 130 kg. This change coincided with the cooling of the ocean at the beginning of the new century.

"Despite ranging widely and foraging deeply in cold waters beyond coastal thermoclines in the northeastern Pacific, elephant seals are impacted significantly by ocean thermal dynamics", conclude the authors.

Le Boeuf and Crocker add that monitoring the mean weaning weight of elephant seal pups can therefore help track changes in ocean temperature cycles.

This press release is based on the article:

Ocean climate and seal condition Burney J Le Boeuf, Daniel E Crocker BMC Biology 2005, 3:9 (28 March 2005)

This article is available free of charge, according to BMC Biology’s Open Access policy at http://www.biomedcentral.com/1741-7007/3/9

Juliette Savin | BMC Biology
Further information:
http://www.ucsc.edu
http://www.biomedcentral.com

More articles from Ecology, The Environment and Conservation:

nachricht Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München

nachricht Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Electrode materials from the microwave oven

19.10.2017 | Materials Sciences

New material for digital memories of the future

19.10.2017 | Materials Sciences

Physics boosts artificial intelligence methods

19.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>