( Female harbor seal pups whose blubber f...)Alaska seal pup diet may hold key to decline of population

The study found that harbor seals pups that were heavier when captured from the wild continued to gain weight and grow regardless of whether the researchers placed them on a high fat or low fat diet. But smaller seals, regardless of which diet group they were put in, continued to lag behind in weight gain and even lost blubber depth.

"Our longitudinal study is leading to a better understanding of the role that fat consumption plays in the life of the harbor seal and could tie the declining population of seals and other marine mammals with the change in availability of seal prey, including herring," lead author Lori Polasek said.

*Paper presentation: "Growth and body condition of harbor seals on high and low fat diets," 12:45 p.m.-3 p.m. Monday April 3, Physiological Ecology and Evolutionary Physiology, 492.3/board #C768. On view 7:30 a.m. - 6 p.m. in the Convention Center Exhibit Hall. Research was by Lori Polasek and Shannon Atkinson of the University of Alaska, Fairbanks and Alaska Sealife Center, Seward, and Anne Hoover-Miller of the Alaska Sealife Center.

The research is part of a much larger effort to find out why harbor seals and other marine mammals are disappearing from the chilly waters off the Alaskan coast. The population decline, which has become a focus of research in the past 10-15 years, is potentially due to a variety of factors, Polasek said, including:

• changes in availability of prey
• warming ocean waters
• pollution
• increased presence of humans who may disturb the animals

Herring, capelin and eulachon are good sources of much-needed fat in the diet of harbor seals, but they have
'"/>

Source:American Physiological Society