Image: COURTESY NOAA
As populations of sea lions and seals in northern habitats continue to decline, satellites are providing scientists with a better understanding of the animals' feeding patterns. Researchers at the National Oceanic and Atmospheric Administration's (NOAA) Alaska Ecosystems Program announced findings this week that may explain what the marine mammals are looking for when they swim hundreds of kilometers from land in search of food.
Using satellites and transmitters attached to the sea mammals, the scientists have been tracking Northern fur seals and endangered Steller sea lions (see image) in the Gulf of Alaska and the Bering Sea for almost a decade. "We want to figure out why animals go to certain areas, what affects their decision-making," Jeremy Sterling of NOAA's National Marine Mammal Laboratory says.
To that end, they combined data they collected in 1999 and 2000 with satellite sea surface topography information provided by Robert Leben of the University of Colorado. This altimeter information reveals the location of currents and eddies as well as ocean temperature and other physical characteristics. "We can definitely see some patterns," Sterling says. "It appears that the animals travel on the edges where the eddies and gyres occur." He suggests the eddies concentrate food supplies that the sea lions and seals exploit.