Heavy rains a suspect in sharks' deaths

SAN FRANCISCO, May 18 (UPI) -- A rash of deaths among leopard sharks in San Francisco Bay may be linked to heavy winter rains diluting saltwater in the bay, wildlife officials say.

State biologists investigating a rash of leopard shark casualties over the past month say they think the body chemistry of the fish may be thrown fatally off balance by the torrents of fresh water flowing into shoreline lagoons where they sharks prefer to give birth and search for food, The San Francisco Chronicle reported Wednesday.

"They might be going into these coves to pup," Carrie Wilson, a marine biologist with the California Department of Fish and Game, said. "If there's more fresh water intrusion and low salinity, it's very tough on these animals."

More than 100 adult and juvenile leopard sharks have been found dead since mid-April, officials said.

The sharks, which can grow to 5 feet long and live 40 years or more, are a common sight in shallow coastal waters from Oregon to Mexico.