Colorado boaters can’t catch a break from those “dam” invasive mussels.
Dreaded, invasive zebra and quagga mussels are more likely to be found in dammed lakes than natural ones, according to a new study.
The dammed lakes, the research found, provide an ideal habitat for the foreign, nuisance species — and they have higher boating activity.
Lakes closest to impoundments are at greater risk because of “jumping” boats to a new body of water, said the study, co authored by Pieter Johnson, a University of Colorado at Boulder assistant biology professor.
The study was published this week in the journal Frontiers in Ecology and the Environment.
“These dams act as stepping stones creating corridors for the invaders to make jumps — often jumps into natural lakes,” Johnson said. “The more impounds you put on the landscape, the more you create these hub habitats.”
Dammed lakes are a good environment because invasive species can withstand and even thrive with the changing water levels.
Researchers compiled data from more than 5,000 water bodies in the Laurentian Great Lakes region for five different invaders: zebra mussel, spiny water fleas, rainbow smelt, rusty crayfish and the plant Eurasian watermilfoil.
In some cases, invaders were 300 times more likely to be found in lakes with impoundments versus natural ones, the study said.
“Zebra mussels were able to make it into Colorado,” said Johnson, who says the state is vulnerable to all five species. “I think that potential for those invaders to make rapid movement in our natural lakes is very high.”
So far, the zebra mussel and quagga mussel, which some describe as the zebra mussel’s “nasty cousin,” have been found in the Pueblo Reservoir and Lake Granby, respectively.
In an effort to stop the mussels from “jumping” into other water bodies, boats are now inspected coming out of the water at both locations.
Inspection programs also have been implemented by the Department of Wildlife and parks officials at the 24 state parks with the highest boat traffic.
“We need to get the ‘clean, drain, dry’ message out to boaters,” said Rob Billerbeck, biological programs manager for Colorado State Parks.
The agencies also have started tracking boat activity during the inspection process to see which reservoirs and lakes they visit, Billerbeck said.
Invaders can clog up boat engines and water-treatment systems.
They also disrupt ecosystems, pulling resources out of the food web by consuming the phytoplankton native species need to survive, Johnson said.
The Aurora Water Board considered closing Twin Lakes and Turquoise Lake — which are owned by the U.S. Bureau of Reclamation — to ensure invasive species don’t infest the waters.
“We’ve expressed concerns about the potential of invasive species (being introduced) into those lakes,” said Alan Ward, a water-resources specialist for the Pueblo water board, which has contracts with the Bureau of Reclamation to store water at those lakes.
“We are still a little concerned that we haven’t closed that loop,” he said. “We just want to make sure those reservoirs aren’t at risk.”
Steve Graff: 303-954-1661 or sgraff@denverpost.com
Culprits in the shell
Zebra mussel
Scientific name: Dreissena polymorpha (Pallas, 1771)
Native to: Eurasia
U.S. introduction: 1988
Means of introduction: Ballast water
Quagga mussel
Scientific name: Dreissena bugensis (Andrusov, 1897)
Native to: Dneiper River drainage of Ukraine (Eastern Europe)
U.S. introduction: 1989
Means of introduction: Ballast water
Impact
Extreme water/food filters removing large amounts of plankton; take in lots of pollutants, which harm wildlife that eat them; clog water-intake pipes
Source: U.S. Department of Agriculture
