If sturgeon could talk

The recent news that some 1500 sturgeon had grounded themselves at low tide in Port Susan made me think of other sturgeon sightings, more than 20 years ago — and ultimately of the Alaska-Yukon-Pacific Exposition, which opened on the University of Washington campus 100 years ago this June.

The fish at Port Susan were evidently so busy eating they didn’t notice the ebbing tide. “Some fish biologists speculate that the sturgeon . . . were hungry for critters found in shallow mud flats,” Michelle Ma wrote in the Seattle Times. “When the tide dropped, the fish were trapped in the estuary’s shallow channels, unable to move across the exposed, muddy ground to deeper water.” When the tide came back in, most of them swam off into the sunset, leaving behind a dozen very large dead fish, some of them 10 feet long.

The first of the older sightings featured something that was very much alive. In the 1970s and early '80s, people reported seeing some kind of sea monster in Lake Washington. It was way too big to be a leaping salmon. It wasn’t a human swimmer or a boat. No one pretended Lake Washington was the next Loch Ness, and the sea monster attracted less interest than the Green Lake caiman of 1986, but the strange sightings in Lake Washington continued.

Then, in the fall of 1987, the remains of a giant sturgeon were found floating at the north end of the lake. The fish (what was left of it) measured 11 feet from nose to tail, and weighed 670 pounds. One mystery was evidently solved. The fish was definitely big enough to have made people wonder. But another mystery was created: What was an 11-foot sturgeon doing in Lake Washington? The annual rings on a thin slice of the fish’s leading pectoral fin ray indicated the sturgeon had lived almost a century. The fish had hatched out in the late 19th or early 20th century. How long had it been in Lake Washington? How had it gotten there?

No one knew, but a 77-year-old man recalled hearing an explanatory story back in 1922: Thirteen years earlier, a pool at the Alaska-Yukon-Pacific Exposition had contained a number of young sturgeon. When the A-Y-P closed down, the fish were turned loose in Lake Washington. Evidently, one of the fish had survived there for more than 70 years, lying low as it were.

Was this plausible? Sure. “It is possible,“ explains University of Washington marine habitat specialist Jim Brennan, who calculated the sturgeon’s age back in 1987. (He counted the growth rings, just as you would count the rings on a cross-section of Douglas fir.) “I have no idea if the sturgeon found in Lake Washington was from the Alaska-Yukon-Pacific Exposition of 1909,” he says. “It is possible that the sturgeon was landlocked, or gained access through the Ballard locks or the [defunct] Black River.”

Dead, the sturgeon couldn’t have been mistaken for much except a floating log. Alive, it could have been the elusive sea monster. Although sturgeon “tend to spend much of their time close to the bottom for feeding and resting,” Brennan explains, “they also exhibit aerial displays of leaping out of the water, or emerging vertically — usually seen with large individuals — similar to a whale ‘spy hopping.’ This was a common observation in San Francisco Bay, where I tagged several thousand sturgeon, and I have also observed this behavior on the Columbia River.”

What would an 11-foot fish have eaten in the lake when it wasn’t jumping? Basically, anything it wanted. “Sturgeon primarily feed on fishes and benthic invertebrates, including smelt, lamprey, clams, and shrimp,” Brennan says. “However, sturgeon will consume a broad range of food items. I have read that a domestic cat was found in the stomach of a sturgeon, and have been told that historically, farmers fished for sturgeon in the Sacramento River with large hooks and whole chickens”

Where the table is set doesn’t much matter. “If a sturgeon were landlocked, it could survive for an extended period of time, as do sturgeon that have become landlocked between the dams on the Columbia River.” In the Columbia, “landlocked sturgeon were prevented from making their seaward migration after the dams were put in place,” Brennan says. “White sturgeon live to be in excess of 100 years, and even though they are naturally anadromous, they are capable of living for extended periods in freshwater.”

“Some of the sturgeon that persist have lived in the river long enough to retain a memory of the Columbia before the dams,” William Dietrich writes in Northwest Passage. “What must the sturgeon have thought when the current finally stilled, the river began to deepen, and they prowled upstream and down to find themselves boxed by walls of concrete, their range now limited to a reservoir pool?” (Calls to sturgeon for comment were not returned.)