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90 °F Forecast | Road Cams Wednesday, May 25, 2005 Today's News | Shop Our Valley | Tempo | Health | Community | Home Delivery | Contact Us SECTIONS Home Page Local News Sports Business Obituaries Life Opinion Tempo AP News Weather Classified Archives Site Map SPECIAL SECTIONS Since We Asked Outdoor Journal Menu Guide How To Guide Health Biz Connection Readers' Choice Real Estate Showcase Real Estate Guide Joy Magazine Homelife Magazine Wedding Guide Passport to the Rogue Valley SHOP OUR VALLEY AutoFinder HomeFinder JobFinder Classified Place an ad TOP JOBS EXTRA Ashland News NIE Personals Movie Times TV Times E The People Volunteer Moving here? eSouthernOregon CUSTOMER SERVICE FAQ's Advertise with us Home Delivery Employment Contact Us Media Kit Oregon Road Conditions & Cams Email Story to a Friend May 15, 2005 Kevin Saylor and Jay Potter collect samples from the bottom of Diamond Lake to record the amount of insect life in the lake. The data will be compared to numbers collected after the lake is poisoned to kill off tui chub, an invasive and destructive fish Mail Tribune / Jim Craven Saving Diamond Lake Tui chubs have turned the ecosystem upside-down, as evidenced by an insect population that’s dying By MARK FREEMAN Mail Tribune Kevin Saylor picks through a tray of Diamond Lake’s benthic ooze in search of insects, and he doesn’t like what he finds. This mix of mud and weeds sports none of the big bugs, like dragonfly nymphs, shrimp-like scuds or leeches, all of which once packed the lake bottom. Saylor’s tweezers instead expose just a few little blood-red worms, a sign that all is not well under Mount Thielsen’s watery reflection. "It’s an indicator of poor water quality," says Saylor, a natural resources specialist for the Oregon Department of Fish and Wildlife. "These bugs can live in water with very little oxygen, where other bugs can’t." In its ecological hey-day, Diamond Lake sported a hefty 292 pounds of bugs per acre of lake bed. But the estimated 200 million tiny tui chubs have out-muscled most insects for food, altering the lake’s food chain. Advertisement Now, surveys like this one reveal 2 pounds of insects per acre. By a bug’s life, the lake is on ecological life-support. "Diamond Lake is in very critical condition," says Jim Muck, an ODFW fisheries biologist in Roseburg. "I’d say it’s life-threatening." The missing insects are one symptom of the chub dilemma that state and federal authorities plan to remedy next year. The agency has secured federal approval to kill off the lake’s chubs, bugs and all in a repeat of a chemical treatment used to eradicate the pest 50 years ago. Biologists believe the leeches, dragonflies and other insects will return to the lake quickly, feeding future rainbow trout populations that could restore Diamond Lake’s reputation as Oregon’s top trout-fishing lake. "When the insects are here, this lake can really produce big trout and lots of them," Muck says. "We need to bring this ecosystem back into balance. There’s just no insect production left." This week’s insect survey is the first of several on-the-water projects scheduled this year in preparation for the scheduled treatment with the fish-killing chemical rotenone in fall of 2006. The U.S. Forest Service plans to restore a channel used in 1954 to draw the lake down 8 feet, or about 20 percent of its current size, before the rotenone is applied. The ODFW also is conducting a string of pre-treatment surveys of insects, water clarity, levels of dissolved oxygen, and alkalinity, Muck says. The baseline data will be compared to post-rotenone measurements that will help the ODFW decide when and how many rainbow trout will be stocked in the lake, which has no native fish. Rotenone-treatment opponents, like Francis Eatherington of the group Umpqua Watersheds, say they will watch the ODFW and Forest Service pre-treatment projects with a close eye. Eatherington prefers mechanically removing the chubs and stocking chub-eating fish species — an alternative the ODFW has panned as ineffective and dashed by the Umpqua National Forest following a two-year environmental study. "We still highly object to what they plan to do," Eatherington says. "There’s just not a lot we can do about it at this time." The chubs, bugs and lake health are all spun together in a complicated web of interaction measured under microscopes and played out lake-wide. In pre-chub years, the varying insects helped support a rainbow trout fishery that generated more than 100,000 angling-days a year on low-budget stocking of up to 300,000 fingerling trout annually. The stocked trout are about 3 inches long when released in June and they initially feed on zooplankton before graduating to insects by Labor Day. The trout grew so quickly and so large that Diamond Lake became the crown jewel of Oregon’s trout lakes. Chubs were discovered in 1992, and many ODFW biologists believe they probably were illegally introduced by a sport-angler who used them as bait. The chub population exploded by feeding on the zooplankton, causing zooplankton levels to crash, Muck says. Zooplankton feed on the lake’s smaller phytoplankton, whose levels subsequently soared after the chubs came in. The phytoplankton have since sapped the lake of oxygen and occasionally trigger summer blooms of algae that can be toxic to people and pets. Similarly, the zooplankton-eating insect population not only crashed, it also shuffled itself in the wake of poor water quality. Before the chubs, small shrimp-like scuds were the most abundant underwater insect, followed by leeches, and the little bloody worms called chironomids coming in a distant third along with dragonflies, stoneflies and mayflies. Now, it’s virtually nothing but the chironomids, and they are less than half as abundant, surveys show. Insect sampling has occurred at Diamond Lake since the early 1950s, and the method has not changed. ODFW technicians will take samples from 23 spots in the lake floor at least three times this year. They will lower a metal scoop that will collect about a pound of lake bottom at a time. Three years after the 1954 rotenone treatment, Diamond Lake’s insects recolonized the lake and by 1957 rose from 2 pounds of bugs per acre to 169 pounds. Muck says he expects the lake’s ooze to be just as creepy and crawly three years after the next rotenone treatment. "We’ll watch these bugs bounce back," he says. "They’ll be the wild bugs of the Diamond Lake system." Chemical-treatment opponents will be watching process closely A Roseburg-based group opposed to the chemical treatment of Diamond Lake to rid it of tui chubs has yet to decide if it will seek a federal court injunction to block the treatment. Francis Eatherington, conservation director of Umpqua Watersheds, said her group may file a suit in U.S. District Court sometime before the scheduled September 2006 application of rotenone to kill more than 200 million chubs in the lake. "We have standing to go there any time down the line, but we haven’t gone there yet," Eatherington says. The group, along with the Oregon Natural Resources Council, lost an appeal through the U.S. Forest Service to have the plan scrapped earlier this year. That exhausted the intra-agency appeals process, opening the door to a federal suit. "Right now, we’re interested in putting our energy into monitoring (pre-treatment surveys) and see how it goes," Eatherington says. The ONRC, however, has no plans to file suit. Steve Pedery, the ONRC’s conservation program manager, says Diamond Lake is an issue over which "we don’t want to see ourselves thrown in front of a train." The group pushed the Forest Service and Oregon Department of Fish and Wildlife to consider a mix of mechanical removal and chub-eating fish stocks to get a handle on the c "We were trying to get something a little less radical for that lake," Pedery says. "We went through the process. They said no. "I wish folks could have given more thought to long-term solutions before-hand," he says. Reach reporter Mark Freeman at 776-4470, or e-mail [email protected] Mail Tribune Home | Local News | Sports | Business | Obituaries | Life | Opinion AP News | Archives | Site Map | Community | Classified Copyright © 1997-2005 Mail Tribune, Inc. All rights reserved. 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