Are Those Cute Seals Among the Culprits?
"The sandy beaches abounded with fine clams . . . gulls, shags and other oceanic birds. . . . Accordingly we were visited from one of the islands by a small party of natives . . . with little pieces of porpoise and seal flesh in their hands which they offered in the most open and friendly manner. And though these presents were not accepted, their generosity and good intentions were rewarded by some little presents." - Archibald Menzies, botanist with the Vancouver expedition, 1792
After a long day crossing the strait, we slip through Cattle Pass on the slack tide and tuck around the lower end of the island into Griffin Bay, where our course is tracked by the sad, black, liquid eyes of some 40 harbor seals hauled out on the rocky outcrop. We drop anchor a few hundred feet offshore from a serene wildlife refuge and watch the hook descend into the bay. Here plankton blooms are sparse and the water clearer, reminding us that the islands are less of Puget Sound than they are of the North Pacific Ocean.
Immediately we are surrounded by perhaps a dozen of those mottled-gray streamlined heads, circling us like earless Labrador retrievers. We are not threatened, just watched with considerable skepticism.
During his six weeks in Puget Sound in 1792, George Vancouver carefully recorded his observations of land and sea, weather and wildlife. And he did not record seeing seals. Even Archibald Menzies, a naturalist whose journal focuses on wildlife, mentions seals only twice. Approached by natives offering "pieces of porpoise or seal flesh," the sailors shuddered and politely declined. Maybe seals were too humanlike or simply too bloody cute; whatever the reason, there would be no seal meat in the English diet.
Our visitors remind us of sailing into Discovery Bay two weeks ago and discovering an ecological whodunit: What has become of a once-prolific run of herring? None of the usual suspects appears guilty. Fishermen have not fished those herring for years. Habitat and water quality appear healthy. And most of their natural predators, including salmon, are declining as well, except for one predator: harbor seals. So suspicion naturally falls on the closest predators, the seals at neighboring Protection Island.
The Pacific harbor seal is a major player in coastal ecosystems from Baja California to the Gulf of Alaska. Pups are born in the summer and weaned in about four weeks. From then on, they're on their own, growing eventually to about 150 pounds, consuming about 10 percent of their body weight a day - up to 15 pounds of fish. Females may live 30 years, males up to 20.
If Puget Sound is in crisis, somebody forgot to tell the seals, who appear to be thriving. In 1978 wildlife authorities estimated there were 10,000 seals in Washington waters. By 1994 the population was at 35,000 and growing 7 percent a year, which means there are about 40,000 today. Of these, more than half are in Puget Sound, where there are more than 200 known "haulouts," the rocks or beaches frequented by seals.
Sea lions, their close cousins who breed in California and winter here, also are increasing; in-season, the population has grown from 100 to 1,000 in 20 years. During our voyage, we have seen no sea lions; they're summering down south. But seals appear everywhere: massed on the beach at Gertrude Island in the south Sound, their weight sinking a pier on Hood Canal, patrolling the shores of Bainbridge Island, Vashon Island and Commencement Bay, or lounging in the afternoon sun at their federal refuge just outside Discovery Bay.
There's the first clue. Two thousand to 3,000 seals now live around Discovery Bay, says Steve Jeffries, a state wildlife official. It's precisely where schools of herring gather early in the year to spawn in Discovery Bay. I scribble the arithmetic. Starting with the mid-estimate of 2,500 seals, I multiply by 10 pounds of fish per day, multiply again by 360 days . . . and gulp. That's 9 million pounds of fish a year, all in one small area. Coastwide, from Puget Sound to California, federal biologists estimate that harbor seals consume 70,174 tons of fish a year, about half of that in Washington.
"They're upper-level predators and highly opportunistic," says Jeffries. And nobody preys on seals. The region's orca whales eat primarily salmon and herring, not seals. For at least a century, the only predator was us. Fishermen viewed seals as competitors for salmon and other fish, and shot them. It was not only legal but encouraged by wildlife authorities. That all changed with the 1972 Marine Mammal Protection Act, which prohibited any shooting or culling of seal, sea lions and their relatives.
Since then, populations have mushroomed, and tempers have flared. Witness the Ballard Locks, where sea lions have feasted on endangered salmon and steelhead while fishermen watch and seethe. Now, with more salmon headed for the endangered-species list, fishermen ask: Why spend millions of dollars restoring salmon runs that will be simply be gobbled up by seals?
One answer might be this: Seals and fish have co-existed for eons, so let nature take its course. But if seals were thriving 200 years ago, why didn't Vancouver and Menzies report their presence? Because they probably were not thriving, Jeffries says. Indians hunted them, as evidenced by the natives' sales pitch to Vancouver's crew.
"To the natives, seals were food!" Jeffries says. "They may also have been competition. I suspect the Muckleshoots or Nisquallys would not have tolerated seals swimming up into their salmon streams, taking fish along the way. They would have been easy to kill."
If so, the seal population may have been controlled, which would explain the sparse reports from Vancouver. Absent human predators, there may be more seals in Washington waters today than in many hundreds of years.
"They have increased because we protect them," Jeffries says. "If this goes on, we could be headed for a crash, and if everything crashes I don't know how we'll restore the system."
Any mere mention of the alternative - killing the critters - appears to be strictly taboo. State officials shudder at the thought.
So much for the prosecution. Here's the case for the defense: Yes, seals will eat salmon and herring. But, as Jeffries points out, seals will eat just about anything that swims. Dozens of isolated seal studies, usually of scat, show widely varying diets. For example, a 1994 study at Gertrude Island, one of the largest seal haulouts in Puget Sound, showed traces of salmon and herring but much larger amounts of whiting, perch, flatfish and squid. Similar results have emerged from studies in Hood Canal, Everett and the Strait of Juan de Fuca.
In one study, state officials reasoned that most Puget Sound salmon come from hatcheries, which tag their fish with tiny wire tags that can be detected with a handheld device. When officials sampled seal scat at Gertrude Island, they found little evidence of salmon tags. And a herring run at the south end of Vashon Island actually is increasing, despite its proximity to hundreds of seals.
The case against harbor seals is mostly circumstantial, says Joe Scordino, a federal biologist. Seals appear to prefer whatever is easiest to catch. And that usually means something slower than salmon or herring. "The predator-prey relationship is never as simple as you'd like it to be," Scordino says. "We get little pieces of evidence here and there, but you're still in the gray zone."
Meanwhile, a study last year by the National Marine Fisheries Service cautioned that culling seal herds could lead to unintended consequences. For example, seals also prey on cod, whiting and other fish that eat herring and juvenile salmon. That study concluded that growing seal and sea-lion populations brought "new problems and conflicts," but could not establish how they are affecting the ecosystem.
So the jury is out. Scientists say they need more research to understand how seals and fish are linked. And even if scientists could find seals guilty, one wonders if 4 million Puget Sound residents could stomach the idea of shooting a creature so high on the cuteness scale.
Here in Griffin Bay, we are a jury of just two. And after a long evening of deliberation, we are hopelessly deadlocked.
