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 Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

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: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>