Tag Archives: seals

Shrinking Snow Depth on Arctic Sea Ice Threatens Ringed Seal Habitat

As sea ice in the Arctic continues to shrink during this century, more than two thirds of the area with sufficient snow cover for ringed seals to reproduce also will disappear, challenging their survival, scientists report in a new study.

The ringed seal, currently under consideration for threatened species listing, builds caves to rear its young in snow drifts on sea ice. Snow depths must be on average at least 20 centimeters, or 8 inches, to enable drifts deep enough to support the caves. (more…)

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Number of Dead California Sea Otters Recovered in 2011 a Record High

*Evidence Builds for White Shark Factor in Otter Mortality*

SANTA CRUZ, Calif. — The California or southern sea otter (Enhydra lutris nereis) appears to be experiencing an unprecedented increase in mortality from attacks by sharks, according to federal and state scientists. 

Since 1968, biologists and veterinarians at the U.S. Geological Survey and California Department of Fish and Game have documented and examined all reported sea otter “strandings” —  counting the number of dead, sick or injured sea otters recovered along California’s coast each year. (more…)

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Fish of Antarctica Threatened By Climate Change

A Yale-led study of the evolutionary history of Antarctic fish and their “anti-freeze” proteins illustrates how tens of millions of years ago a lineage of fish adapted to newly formed polar conditions – and how today they are endangered by a rapid rise in ocean temperatures.

“A rise of 2 degrees centigrade of water temperature will likely have a devastating impact on this Antarctic fish lineage, which is so well adapted to water at freezing temperatures,” said Thomas Near, associate professor of ecology and evolutionary biology and lead author of the study published online the week of Feb. 13 in the Proceedings of the National Academy of Sciences. (more…)

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High-Tech Software and Unmanned Planes Allow Scientists to Keep Tabs on Arctic Seals

A novel project using cameras mounted on unmanned aircraft flying over the Arctic is serving double duty by assessing the characteristics of declining sea ice and using the same aerial photos to pinpoint seals that have hauled up on ice floes.

The project is the first to use aircraft to monitor ice and seals in remote areas without putting pilots and observers at risk, said Elizabeth Weatherhead of the University of Colorado at Boulder, who is leading the study team. Weatherhead is a senior scientist at the Cooperative Institute for Research in Environmental Sciences, a joint venture of CU-Boulder and the National Oceanic and Atmospheric Administration. (more…)

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Squid Studies Provide Valuable Insights Into Hearing Mechanisms

The ordinary squid, Loligo pealii—best known until now as a kind of floating buffet for just about any fish in the sea—may be on the verge of becoming a scientific superstar, providing clues about the origin and evolution of the sense of hearing.

In a hangar-like research building at the Woods Hole Oceanographic Institution (WHOI), biologist T. Aran Mooney is exploring virtually uncharted waters: Can squid hear? Is their hearing sensitive enough to hear approaching predators? How do squid and other marine species rely on sound to interact, migrate, and communicate? Will the burgeoning cacophony of sound in the ocean disrupt marine life’s behavior and threaten their survival? (more…)

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