Mike Castellini ~ Polar Visionary

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Medical and Management Advances

Steller Sea Lions
This project started with a simple idea. In the field, researchers can only work with an animal for an hour or so. With the capacity of the SeaLife Center, animals could be brought into the lab for much longer periods. Even though the Steller sea lion is endangered, the Center has quarantine facilities that allow them to be brought in and worked on in the lab - unique among endangered species. The juvenile Stellers stay for six weeks, during which time they are implanted with life history transmitters that record and store data. After being released, the transmitters stay with the animal. When the animals die, the device will pop to the surface where it can be found by GPS and the data downloaded, giving researchers a better idea about causes of mortality. "This project has far exceeded all expectations," says Mike.
Dr. Michael Castellini moved to Alaska in 1989 in order to study marine mammals – what it takes for them to live in the ocean, from both physiological and medical perspectives. For years this had required fieldwork in order to observe the animals and get samples. The opening of the Alaska SeaLife Center meant that marine mammals could be observed in captivity and brought in for testing and data sensor implants and then released. (See the Steller Sea Lion Project, below.)

"Nothing quite beats sitting on a beach holding a brand new seal pup."
In Alaska, marine mammals are co-managed between subsistence utilization and the Marine Mammal Protection Act. While these two perspectives may be in conflict at times, there is agreement on the concern about declines in population as well as impacts on the ecosystem from climate change and fishing. Mike's research has been key in the understanding of what might be causing declines, and thus how to manage these populations. "We have to use data that we have now to try to interpret backwards in time," says Mike. "First we have to discover if animals in the field are healthy or not - how do you determine their relative health?"

What appealed to Mike about working with marine mammals was that they offer a unique comparative view of how physiology works. He saw how he could exploit that comparative view to understand oxygen chemistry, adaptation to pressure, adaptation to cold. Other scientists have looked in additional areas, such as hydrodynamics or cognitive issues.

Mike has studied Steller sea lions, whales, sea otters and other mammals, what types of food and fuel keep them going, how they digest fish, and starvation chemistry. More recently he has studied how they hold their breath when they sleep, in conjunction with Sudden Infant Death Syndrome (SIDS) research being done at the National Institutes of Health (NIH). He has been out on beaches from Barrow to the Aleutians, looking at effects from the Exxon Valdez oil spill on animals' blood chemistry. "It's always been an adventure," says Mike. "And I'd do it all over again."

Sea lion
The Steller Sea Lion Project
Monitoring juveniles project description
Sea lion
The Steller Sea Lion Project (Raw Footage)
Footage from the field – capturing the juveniles