SHARK'S CAPTURE REVEALING : `BIG EMMA' OFFERS CLUES TO MIGRATION.

Byline: John Woolfolk Knight-Ridder Tribune News Wire

Big Emma, a huge shark that once thrilled visitors at the Monterey Bay Aquarium before her release two years ago, swam more than 400 miles home to Humboldt Bay only to become the prize catch of a sport fisherman Thursday morning.

An unidentified angler landed the 9-foot, 8-inch and 276-pound sevengill shark at 2 a.m. by hook and 50-pound line after a struggle that lasted more than four hours, said Patrick Collier, a state Department of Fish and Game biologist.

Back in the Monterey Bay area, shark scientists who had worked with Emma, the largest of her species ever on display, were both saddened by her loss and intrigued by the information gleaned from her capture so far from where she was released.

``It's always sad to hear that one of our sharks has been hit and sunk, so to speak,'' said Sean Van Sommeran, director of the Pelagic Shark Research Foundation, which helped the aquarium tag and release Emma off Monterey in June 1994.

``But it's illuminating at the same time,'' said Van Sommeran, whose Santa Cruz-based organization has tagged more than 100 sevengills in San Francisco Bay since 1993. Many of those have been recaptured in the same area, suggesting the sharks either don't roam far or habitually return to the same place, he said.

Gil Van Dykhuizen, a biologist at the Monterey Bay Aquarium who had taken care of the big lug during her four years on display, said little is known about the habits of sevengill sharks, a bottom-dwelling species that can swim 2,700 feet deep.

``There's not much of a database out there as far as tagged sevengill sharks that have been recaptured,'' Van Dykhuizen said.

Aquarium researchers were encouraged to learn that Emma had apparently done well for herself since her release.

``The fact that she was able to home back to her original stomping grounds is good evidence that an animal is able to relocate itself back to its original territory after being part of a shark collection in an aquarium for four years,'' Van Dykhuizen said.

When she was ``collected'' in July 1990, Emma was so big that biologists thought she was pregnant, said aquarium spokesman Ken Peterson. Once in the tank, she became a star attraction.