National Geographic : 1992 Oct
than answers. I put some of them to Bill Aron at NMFS. "Animals are better oceanographers than we are," he told me. "For instance, the Steller sea lion population collapse started at a time when there was a vast increase in pollock, their principal food. Why? We don't know. But they are telling us something is happening." Today sea lions are helping to report their own activities by way of radios and instru ment packages glued to their fur in a multi million-dollar government study. "The radios transmit data to satellites," said Tom Loughlin, of the NMFS Marine Mammal Laboratory. "We've learned that in the breeding season they go 20 to 25 miles off shore to feed. Their dives last about two min utes, at depths between 65 and 330 feet. "The next step will be to monitor fishing within a 20-mile radius of a rookery, to see what effect it has on population trends." To learn more, I visited Alaska Depart ment of Fish and Game biologist Lloyd Lowry, director of the Steller Sea Lion Recovery Team. "We are finding that adult females are poorly nourished, so what is happening near the rookeries may be critical," he said. "Fishing on spawning shoals of pollock could be particularly damaging, because the high calorie roe-bearing fish are a preferred food for the sea lions late in pregnancy. If they don't get the right food at the right time, it may be that they spontaneously abort." Neither Loughlin nor Lowry believes that number crunching-juggling fishing statistics and population estimates-provides enough information for management. "You must have a conceptual model of each creature's relationship to all the other creatures and to the whole," Dr. Lowry said. "Remember, the North Pacific was changed greatly by whaling. Large whales were very abundant, numbering in the tens of thousands. When they disappeared, millions of tons of food was freed up for pollock, Living doll, nine-month-old Lorianne Koonooka waits as her elders launch a whale huntfrom the beach on St. Law rence Island. Cushioned by modern amenities, residents of the Bering Sea's largest island still ride the waves in walrus-skin umiaks of their ancestors. herring, and salmon. Did that create an arti ficially high biomass of forage fishes? What kind of ecosystem did we start with?" Fisheries managers will soon have more information to work with thanks to a new policy of placing some 600 NMFS observers on fishing vessels, at a cost of seven to eight million dollars to the industry, to monitor the catch and bycatch and gather biological data. Enforcement of rules will be strengthened. "Up to now, all we've required is that fisher men throw the bycatch back," said Russ Nelson, manager of the observer program. "Now we have a 'penalty box' system for excessive bycatch. Penalties range from a warning to boat seizure. It doesn't bother the careful ones. Dirty fishing is just a habit. Clean fishing is a skill."