The National Zoo's senior male gray seal, Gunnar, died June 22. Keeper and veterinary staff had been managing his declining health for several months. A final pathology report will provide more information. He was 38 years old. The lifespan of a wild gray seal is usually 25 or 30 years. Typically, male gray seals in human care live no more than 30 years; female zoo seals can live close to 40 years.

Gunnar arrived at the National Zoo in January 1979 from the Naval Oceans Systems Center in San Diego. When he was 6 months old, Navy researchers trained Gunnar to perform underwater tasks during the Cold War. Gray seals can dive down to 475 feet deep and remain underwater for 20 minutes, so they were considered an efficient and effective means to retrieve items from the ocean floor. In his career as a Navy seal, Gunnar learned how to insert and remove equipment, use a screwdriver and turn a large wheel valve.

Most Zoo animals participate in a breeding program called the Species Survival Plan. The SSP scientists determine which animals to breed by considering their genetic makeup, nutritional and social needs, temperament and overall health. Born in Iceland in November 1973, Gunnar's genes were not represented in U.S. zoos, making him a valuable breeder. Gunnar sired two female pups named Kara and Kjia in 1983 and 1990, respectively, who were born at the National Zoo. They currently live at Adventure Aquarium in New Jersey but will return to the Zoo's new American Trail exhibit after it opens Sept. 1.

Gray seals are native to the North Atlantic. North American gray seals typically live on the rocky outcroppings of Canada's east coast, though scientists have spotted them as far south as New Jersey. The International Union for Conservation of Nature lists the gray seal as least concern. Efforts to stop hunting and reduce the number of seals trapped in fishing nets have greatly contributed to the stability of their population.