Voracious mammals feasting on migrating salmon, steelhead

Glen Martin, San Francisco Chronicle January 15, 2007

Some fishery advocates say seals and sea lions are eating too many of California's salmon and steelhead, contributing to the possibility of shortened fishing seasons and higher seafood prices.

Fish-loving mammals like California sea lions and Pacific harbor seals tend to congregate at river mouths, forcing migrating fish to swim a lethal gauntlet during the spawning season. For fish runs already threatened by habitat destruction and water diversions, voracious seals and sea lions could constitute a tipping point, some experts believe.

Surveys of steelhead on Santa Cruz County's San Lorenzo River and Scott Creek show about 40 percent of the fish suffered tooth or claw marks from harbor seals, said Larry Wolf, director of the Monterey Bay Salmon and Trout Project.

"I've seen up to 20 seals in San Lorenzo at one time," Wolf said. "Any fish trying to get up or down the creek was in major jeopardy.

"These creeks may only have 30 to 50 spawning coho (salmon) returning a year," he said. "It doesn't take much to wipe out the run."

Bob Strickland, the president of United Anglers of California, a sport fishing group, said there are too many seals and sea lions and too few salmon and steelhead along the West Coast.

"They're everywhere," Strickland said. "I was fishing the Cowlitz River in Washington and they were miles up river, chasing the fish. They're up the Sacramento River now. I fished Monterey Bay not long ago and hooked 11 salmon. I pulled up 10 heads and only one complete fish. The sea lions were biting them off the hook."

Michael Weise, a postdoctoral researcher at UC Santa Cruz, said studies indicate the marine mammals take between 5 to 15 percent of salmon returning to streams in Oregon and California. Research also indicates that seals and sea lions eat between 12 and 15 percent of salmon hooked by ocean anglers, he said.

About 240,000 California sea lions and 60,000 Pacific harbor seals live off the U. S. West Coast. It's not simply that they eat thousands of salmon that might otherwise be caught by people, say fishermen -- the critters may also negatively affect federal fishing regulations.

The health of California's most endangered fish runs determines the duration and quotas for the commercial salmon season. Last year, the California season was greatly limited because of the Klamath River's paltry chinook and coho salmon populations. Shorter fishing seasons hurt the paychecks of commercial fishermen and can cause consumer fish prices to rise.

There are no easy solutions. Seals and sea lions are covered under the U.S. Marine Mammal Protection Act. While the act allows for the removal of troublesome animals to protect endangered species, such waivers are hard to get.

Oregon and Washington state officials have applied to the fisheries department of the National Oceanic and Atmospheric Administration to control seals and sea lions in order to protect endangered runs of Columbia River salmon. NOAA Fisheries hasn't yet approved the request.

But federal regulators are aware of the problem, said Rod McInnis, the southwest regional director for NOAA Fisheries.

"We've had concerns for some time, especially about sea lions on the Klamath," McInnis said.

The salmon are also important to the Yurok Indian tribe, whose ancestral lands include the mouth of the Klamath. The fish are a food source and essential to tribal religious ceremonies. Because tribes exercise a significant degree of sovereignty over their lands, the Yurok possibly could kill seals and sea lions on tribal territory without federal permission.

Troy Fletcher, a Yurok tribal member and a consultant to the tribe on natural resource issues, said the Yurok are considering their options.

"Historically, the tribe has harvested seals and sea lions for consumption, and that is one option we'll consider," Fletcher said. "The tribal council will conduct a review that will be prudent, cautious and respectful. And whatever decision they make will be made under the sovereign authority of the tribe."

While seals and sea lions eat a lot of fish, fishery advocates and regulators agree they're not the primary problem confronting salmon and steelhead.

"It's a touchy subject," said Zeke Grader, the executive director of the Pacific Coast Federation of Fishermen's Associations, a commercial fishing lobby.

Seals and sea lions can hurt runs, but the destruction of spawning habitat and water diversions are bigger problems, Grader said.

William Kier, a Humboldt County fisheries consultant who specializes in the Klamath runs, agreed. Seals and sea lions, he said, evolved along with salmon and steelhead, so they shouldn't be scorned for doing what comes naturally: eating fish.

"Salmon and steelhead have always had to deal" with predators, Kier said. "They've always had to deal with fluctuating ocean temperatures and changing food supplies. What's new in the equation is the massive destruction of freshwater habitat we've seen in the past few decades. That's what has to be remedied."

E-mail Glen Martin at glenmartin@sfchronicle.com.