Bottom of food chain a warning the top
VAIL – Some of the tiniest inhabitants of Gore Creek – aquatic bugs – could play a big role in determining how clean that increasingly polluted and urbanized mountain creek needs to be.A new study of the bugs in the creek – midges, mayflies, stoneflies and caddisflies – shows clean-water-loving species of aquatic bugs are conspicuous by their absence when compared to similar streams that aren’t affected by pollution. The pollution in Gore Creek is sediment that is beginning to choke parts of the creek, smothering the habitat favored by the insects that prop up the food chain. The bugs live in the spaces between rocks that are getting covered by sand.The biological findings may ratchet up the political pressure to clean up the creek because it points to an increase in the amount of sediment infiltrating the waterway. Some fear the sediment may choke Vail’s famed gold medal trout fishery on Gore Creek.Quite a bit of sediment occurs naturally, but in urbanized areas like Vail, it also comes from traction sand used to keep Vail Pass open in winter, runoff from construction sites, stormwater runoff from roads and parking lots. Two years ago some of the sediment in the stream came from a sinkhole under I-70 in East Vail that closed the highway. A culvert carrying a creek collapsed under the highway and washed tons of dirt into Gore Creek when the stream was diverted.Bug’s taleThe bug study was conducted by U.S. Forest Service biologist Brian Healy to determine what level of sediment the creek can accept and still remain a viable ecosystem. It’s part of the cleanup effort of Vail Pass that aims to determine how much of the estimated 150,000 tons of sand from more than three decades of road sanding, can be cleaned up and how much can be left to Mother Nature. The $15,000 study was paid by the town of Vail and the Eagle River Watershed Council, a river watchdog group.
“Any way you slice it shows there’s a sedimentation problem,” Healy said, adding that because the study is in its first year, it is difficult to determine what the trends are. The bug study shows the number of bug species and number of bugs that don’t tolerate sediment pollution are down by 40 or more percent.Adding urgency to efforts to clean up the creek is the knowledge that gravity is at work. One of the main tributaries of the creek, Black Gore Creek, which runs along I-70 from the top of Vail Pass to East Vail, is listed as “sediment impaired” by the U.S. Environmental Protection Agency. If the sedimentation worsens, the EPA could mandate an immediate and costly cleanup.Traction sand has choked the creek, burying the aquatic habitat under the sediment, and it’s washing ever closer to and is beginning to show up in Vail’s 3.5-mile trout fishery that runs west of Lionshead to the Eagle River. That stretch is believed by town leaders to add millions in business each year because it draws hundreds of fishermen seeking the hulking trout that live there. When it was last surveyed by the Colorado Division of Wildlife five years ago, the stream was called “robust” because it contained 60 large trout per-surface acre. The gold medal designation requires a minimum of 12 trout 14 inches or longer, and 60 or more pounds of trout per acre.During the last fish census another fish, the sculpin minnow that trout eat, was found in good numbers, Division of Wildlife aquatic biologist Allen Czenkusch said. That, he said, is an indicator that the gold medal stretch remains healthy because sculpins can’t tolerate water pollution.Biology and ballotsThe news that the creek is beginning to show the impacts of 45 years of human activity along its banks is a red flag for Vail environmental officer Bill Carlson and others. Carlson wants the Division of Wildlife to re-survey the creek to see if sediment pollution has begun to hurt fish in the gold medal stretch. Earlier this month, Vail passed stricter regulations on how contractors and developers handle the runoff from their construction sites, Carlson said.
It’s timely because Vail is in the midst of a $1 billion renovation of up to 20 properties in town that will be completed over the next five or six years. Many of them are astride Gore Creek.How best to control sediment, and who is responsible for doing so, is where the science of biology and subjectivity of politics intersect.”There are sediments in the creek,” Czenkusch said. “Where opinions diverge is how much there is and where it’s coming from. It’s an oversimplification to say it’s all coming from the pass.”A consortium of governments and governmental agencies are engaged in a $20 million cleanup of the sediment sand on Vail Pass. While the cleanup has helped slow how much new sand enters the creek, a tougher issue, says Carlson, is the estimated 150,000 tons that are slowly migrating toward the creek on the steep hillsides lining I-70 over Vail Pass.For the Colorado Department of Transportation, the environmental issue of too much sand in the creek has to be balanced against keeping the road open in winter and making it as safe to travel as is possible. In cooperation with other entities the transportation department has built 48 sand traps that strain sediment when the snow melts. Those traps are cleaned out each year and the sand helps to build sound barriers along the highway in Vail.Healy’s study was completed last fall on Gore Creek in East Vail, near Ford Park and in West Vail, as well as on other nearby streams that are not affected by human activities. He’s drafting Healy noticed large sandbars in Gore Creek in areas that should have been filled only with the rounded river cobbles that mayflies and other cold water bugs like, he said. ‘Blast’ of nutrients
But the sand may not be affecting how many trout are in the gold medal part of the stream as much as something that seems antithetical trout- a sewer plant. The sewer plant outflow at Forest Road, just west of Lionshead, supercharges the stream and causes the population of certain bugs – and trout -to boom.”It provides a blast of nutrients,” said Pete Walker of the Division of Wildlife.Bill Perry, who owns Fly Fishing Outfitters in Avon, has been fishing Gore Creek for nearly a quarter century, and said the fishing remains good, probably as good or possibly even better than when the stream achieved the gold medal status in the mid 1980s. But, he added, fish are becoming “hook -educated” and are getting much harder catch.The largest trout he’s netted from the tiny creek was 20 inches long and weighed about four pounds. Perry credits the sewer plant for keeping the stream open in winter and helping to feed the bugs upon which trout feed.It’s not clear if the sediment and drop in clean water-loving bugs was caused by a one-time occurrence like the sinkhole or if by other factors. But most experts agree on one thing – if the problem that’s causing bugs to decline is fixed, bug numbers spring back very quickly.While biologists like Czenkusch acknowledge there is a problem with sediment, he says, the severity remains debatable.”I’m concerned,” he said. “I don’t have any reason to believe the sky is falling. Any stream where you find 16-inch and 17-inch trout can’t be that badly broken.”But that sentiment isn’t shared by Caroline Bradford, director of the Eagle River Watershed Council.”If you see sections of a stream covered by sediment, something’s wrong,” she said.Staff Writer Cliff Thompson can be reached at 949-0555, ext. 450, or firstname.lastname@example.orgVail Colorado