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ODFW to wage war on unwanted chubs MT file photo ODFW biologist Dave Loomis, left, and technician Jay Sturdivant net and count thousands of tui chubs using a trap net in 1997. Loomis hopes to use a commercial herring net to trap and remove millions of the illegally introduced chubs during an experiment this summer. By MARK FREEMAN Picture standing along the pine-lined shore of Diamond Lake, the watery reflection of Mount Bailey broken by the chugging of a fishing boat more at home on the high seas than in the High Cascades. Imagine a commercial fishing boat, dragging a net the size of a city lot over Diamond Lake's insect-rich mud flats. And sport-fishermen standing by, cheering. A decade ago, state fish biologist Dave Loomis couldn't fathom such a sight. But he's faced with a lake overrun with unwanted tui chubs. Now, something as crazy as using commercial fishermen's ocean nets in the war against tui chubs sounds promising enough perhaps to become reality this summer. The Oregon Department of Fish and Wildlife hopes to experiment with ways to knock back the lake's enormous chub population and help struggling rainbow trout get a fin-hold again in the once-popular sport-fishing waters. Those experiments likely include stocking large predatory trout or salmon in the lake to eat as many chubs as possible, and also to use commercial fishermen to net and remove as many of the lake's chub as they can. "That's the idea we're kicking around," says Loomis, from the ODFW's Roseburg district office. "We think it's a good possibility, obviously, or we wouldn't be pursuing it." Loomis' pursuit is testimony to just how bleak Diamond Lake's chub problems have become and how desperate the efforts have come to address it. Millions of chubs are feasting so heavily on the lake's abundant insect population that there is no room or food left for the trout stocked for fishermen. The agency wants to draw the lake down and chemically treat it to kill off all the fish, then restock it with rainbow trout. But that plan is mired in environmental study and likely won't occur until 2003 -- if at all. So Loomis hopes to try some interim efforts to help decrease the chub population -- including tapping the expertise of commercial herring fishermen like Bob Shoans of Newport. Shoans, 48, has been working with Loomis on possibly using tactics and gear for netting ocean herring on the lake's chubs. Either dragging large trawl nets around or using small-mesh herring seines, Shoans believes the tactics used to mine the sea can certainly dig up a few million chubs. "I think we can knock that (chub) population down," Shoans says. "Given the size of this lake, it's a lot smaller area to fish than we're used to. It's gotta be harder to catch a fish out there than in a lake." Diamond Lake was once a mecca for fly-casters and others who saw the lake as the jewel of the Cascades. Its cool waters created bountiful insect hatches that turned stocked fingerling trout into fat 20-plus inchers that made Diamond the state's most-fished trout lake. Then one sport-fisherman ruined Diamond Lake for everyone. Some unknown angler brought tiny tui chub to the High Cascades lake as "minnows" for bait. Now, these trash fish ballooned in numbers to more than 26 million -- 22 million of which are less than two inches long. The lake's once-prolific hatchery rainbow population has crashed to 10,000 or less, giving Diamond Lake a new reputation among trout anglers as a place to ignore. Similar infestations occurred in the 1940s and again in '54. Each time, the lake was chemically treated with rotenone and restocked. Loomis wants to repeat that treatment again, and the ODFW has set aside $400,000 to help pay for it. But environmental studies must first be done. If rotenone is used, it won't be for at least three years. Last year, the agency began to experiment with stocking larger, more predatory trout in Diamond Lake. The fish were a big hit with anglers, and the predatory trout definitely feasted on chubs. But Loomis hopes to experiment this year with stocking other species, such as brown trout and other strains of rainbow trout, then quantify if and how many chubs these other fish eat. But predatory trout alone aren't enough. Last summer, Loomis began to wonder out loud whether commercial nets could be used to capture and kill as many chub as possible until a final solution could be addressed. "You can't remove 90 percent or 100 percent of them with nets," Loomis says. "But I'm confident you can remove a lot of the tui chub." The trick will be to remove enough chubs that trout can start feeding on insects again and survive. "The thing is, we want to see if it's possible to knock down the chub population enough to have a food chain pop up that at least starts to grow some trout," Loomis says. "I think we can." Shoans, too, is confident. But he first needs to learn more about the lake and the chub's behavior to determine which netting techniques will work best. If the fish ball up in thick congregations, then a seine could be used, Shoans says. But if the fish are less concentrated, then dragging a net around the lake would work better, he says. "There's a real knowledge of fish behavior that's lacking right now," Shoans says. But Shoans believes something can be worked out. "In a couple months' time," Shoan says, "I think we could get 70 percent of the chubs in there." Loomis is less optimistic. Since most of the chub are less than an inch long, they likely won't get netted. Instead, he wants netting to concentrate on the 4-inch-long spawning fish -- killing off enough of those to stop the chub's population growth. And any netting must be done in a way that doesn't wipe out the same Diamond Lake trout the ODFW is trying to save. "We can't put these 2-pound rainbows in and, in front of the anglers, turn around and net them and kill them," Loomis says. Loomis is drafting a written proposal for the stocking and netting experiments. Then he will ask the Oregon Legislature to allow the agency to use some of the $400,000 set aside for rotenone treatments to fund these experiments. If he's successful, Diamond Lake could sport a small commercial fishing fleet of its own this summer. Staff writer Mark Freeman covers the outdoors for the Mail Tribune. Call him at 776-4470, or e-mail him at [email protected] ) Outdoor Journal Today's Edition : News | Sports | Business | Weather | Tempo | Classifieds Mail Tribune Mail Tribune � 2000 -- Medford, Oregon USA