It was the lead story on every televised newscast leading up to the Christmas holiday. A dead pond Koi had been spotted in the McKenzie River at Armitage Park. The fish was bright orange, a bit tattered, and weighed about 3-4 pounds.
Of course, the fish stood out like a sore thumb in the seasonally turbid waters of the lower McKenzie River and was reported to the local office of the Department of Fish and Wildlife in Springfield by a concerned citizen. Sadly, it’s obvious that the fish did not find its way into the McKenzie.
It could have been an accident – or someone ignoring signage at the riverside park about the dangers of releasing non-native fish species into our lakes and rivers.
Our local news outlets have regularly included other stories about the negative outcomes of releasing aquarium fish and turtles into the wild. Authorities found it had been somewhat of a tradition for fish and other aquarium species used in the educational process to be “set free” at the end of the school semester. Fortunately, that is no longer a practice, but you can still find gold in many of those ponds.
The fact is that many (but not all) aquarium fish require an ideal habitat to spawn successfully. The single koi found in the McKenzie had been someone’s “pet fish” of a species breed for hundreds of years as a “pond fish” and was probably hand-fed for most of its life. Although it did capture everyone’s attention, koi typically spawn when water temperatures reach above 65°; that naturally occurs in late spring or early summer. But in the McKenzie River the annual average water temperature is only about 50 degrees and never reaches more than 62 degrees, making the likelihood of a koi outbreak pretty low. I strongly endorse the message: We can’t toss any non-native fish into our local waterways. But the news reporting failed to mention that there is already any number of non-native fish that are far more predatory – that will eat anything, aquatic or terrestrial, including salmon smolts. They already have attained a solid foothold and continue to thrive in our local waterways, mostly unchecked.
The list (though not complete) of freshwater fish native to Oregon is actually quite small, and including several types of lamprey, a couple of types of sturgeon, variations of bottlenose suckers, minnows, and sculpin. Of course, there are salmon, of which there are seven different types, two types of trout, summer and winter steelhead, and bull trout, a member of the char family. Every other fish that now swims in Oregon freshwater waters are “invasive.”
Prior to 1900, there were no “sunfish species” in any of Oregon’s rivers or lakes until largemouth bass. With the approval of fisheries managers, largemouth were planted in a portion of the lower Willamette River – the bass were transported across the county by train in barrels. It is believed that every other sunfish, bluegill, crappie, and perch had all just been scooped up along with the bass. They possibly served as food for the bass, but they also ended up in the Willamette. The introduction of “smallmouth bass” in about 1910 had been rejected by early fisheries, but a couple of years later, smallmouth was discovered in the lower Willamette, and walleye mysteriously appeared shortly after the completion of the Columbia River Hydro System.
Both fish are native to the Midwest, quickly filled the niche they were given, and have become problematic.
In no context is the discovery of a koi in the McKenzie or Willamette rivers acceptable. But smallmouth bass and walleye are not as obvious. I’ve been part of the sport fishing community for five decades. I recall when walleye were first caught in Lookout Point Reservoir in the 1980s, and now they are often caught in the Willamette below Dexter Dam. Smallmouth bass have spread up the Willamette to Harrisburg. A walleye and smallmouth can survive and even thrive in a temperature from below 40 degrees to more than 80. The story about invasive fish is far from over – stay tuned.
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