by Scott Sadil
Like most things fishing, questions about shad, another profligate exotic here in the Columbia River basin, arrive with a season. About the same time cherries ripen, those luscious Bings that remind you, once again, why life is worth living, the daily count of American shad (Alosa sapidissima) passing through the Bonneville Dam fishway reaches mind-boggling numbers – an astonishing run steeped in the tragic irony of the river’s depleted numbers of chinook salmon and the historic disappearance of its once-fabulous “June Hogs.”
Fifty, sixty, seventy-five pounds or more, June Hogs were the largest chinook, with the strength and energy reserves needed to travel over 1,000 miles upriver to spawning grounds in Canada, a journey aborted shortly before WWII on completion of Grand Coulee Dam. Access to spawning gravel was further reduced, in the early 1950’s, by Chief Joseph Dam, another facility built without means of fish passage, a peculiarly ominous decision in light of the dam’s historically-shortsighted name.
Meanwhile, shad numbers have exploded. Nobody is quite sure why. Introduced to the West Coast in 1871, when angling aquaculturalist Seth Green outfitted a train car to carry fish cross-country and ended up dumping 10,000 fingerlings into the Sacramento River, shad spread quickly. By 1880 they had arrived in the Columbia; in 1885, shad from the Pennsylvania reach of the Susquehanna River were deliberately planted in the Columbia, as well.
Dams, once again, might provide answers as to what’s going on. Biologists believe that the freshwater habitat created by dam reservoirs is ideal for spawning and rearing shad. They point to evidence showing that after The Dalles Dam was finished, in 1956, the average number of adult shad counted at Bonneville Dam, farther downstream, increased from 15,000 a year to over 330,000 between 1960 and 1964.
Now that number is closer to 4,000,000. That’s nota typo. The actual run, in fact, may be much larger; many fish spawn below the dam and therefore don’t get counted.
Give or take a million, a run that size generates interest – even among the small number of fly rodders willing to search out casting lanes between more congenially-spaced gear anglers.
A few deep bends in a two-handed six-weight, however, still don’t stop the questions. Given the multitude of spawning fish, the number of juvenile shad, heading downstream in fall, must approach a gazillion. There’s every reason to believe that these outmigrating shad, baitfish in size, are a big reason the populations of predaceous walleye and smallmouth bass, two other exotics, have also increased dramatically in the lower Columbia, as have the numbers of native northern pikeminnow.
All of these species, need I add, have to eat throughout the year – a dietary imperative mitigated each spring by the downriver migration of salmon and steelhead smolts.
Plug into that same equation the distorted numbers of terns, cormorants, pelicans, osprey and other fish-eating birds of prey, their populations artificially increased by the autumnal infusion of bite-sized juvenile shad, and you can begin to see that all of these adult spawners in the river, even that nice one bulldogging in heavy current at the end of your line, don’t come without a cost.
Nor questions.
I wish I had some answers.
The best I can do is suggest that if you’re in the neighborhood, now’s the time to grab a handful of darts and swing up a few fish.
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The first story Gray’s angling editor Scott Sadil sold to the magazine was about Northwest shad fishing. His thesis hasn’t changed: it’s a lot of fun.
