Colorado Parks and Wildlife decontaminated more mussel-infested boats in 2019 than in 2018, but inspectors again kept the invasive and destructive mussels out of the state’s lakes and reservoirs.
Statewide, 481,543 inspections were conducted, 7,000 more than in 2018. A total of 22,947 boats, 281 with attached mussels, were decontaminated, compared with 19,111 in 2018.
The increase in the number of fully infested boats frustrated CPW officials: In 2019, 86 boats were fully infested, a 40% increase compared with 51 in 2018. Two were stopped from entering McPhee Reservoir.
In 2017, only 16 mussel-infested boats were intercepted statewide.
McPhee Reservoir reported 7,893 inspections, 306 decontaminations and two interceptions of fully infested boats in 2019, up from 7,520 inspections and 274 decontaminations in 2015, according to CPW. McPhee is considered a high risk for mussel contamination because of its proximity to the mussel-infested Lake Powell.
Mussels can clog up pipes and important infrastructure, cover docks, shorelines, rocks, any hard surface and can ruin powerboat engines.
Although Colorado remains mussel-free, CPW officials are concerned about the increasing number of boats that need decontamination.
“CPW will not let down its guard to keep invasive aquatic species out of the state,” said CPW spokesman Joe Lewandowski in a news release.
CPW’s Aquatic Nuisance Species Program is charged with protecting the state’s water resources and infrastructure from the invasive species.
“Colorado remains free of adult zebra and quagga mussel-reproducing populations,” said Elizabeth Brown, CPW invasive species program manager.
She credited inspections, early detection, and education and enforcement efforts.
Other states that have mussel infestations include Arizona, Utah, Kansas, South Dakota, North Dakota, Oklahoma, Texas and California.
Brown said she’s concerned about the increase in infested boats entering Colorado.
“This growth trend is directly related to the growing threat invasive mussels pose to Colorado’s water infrastructure, natural resources and outdoor recreation,” she said.
A fully formed adult zebra or quagga mussel has not been reported in Colorado waters. However, mussel larvae, known as veligers, were detected 2017 in Green Mountain Reservoir in Summit County, and the reservoir is still considered suspect for quagga mussels.
CPW confirms all visual detections with DNA analysis to confirm the genus and species of the mussel. If no detections are verified in 2020, Green Mountain Reservoir will be delisted.
In 2019, crews sampled 179 standing, and four flowing, waters statewide for veligers. In addition to the sampling efforts performed by CPW, the National Park Service contributed 38 plankton samples. There were no detections of zebra or quagga mussels in Colorado.
CPW works in partnership with dozens of other agencies, counties and municipalities throughout the state. Help from the partners is critical in maintaining a mussel-free Colorado, Brown said.
In 2019, CPW authorized 72 locations to perform inspections and decontaminations.
Colorado waters where the most inspections were conducted last year are:
Pueblo Reservoir: 73,435 inspections, 2,275 decontaminations.Chatfield Reservoir: 60,998 inspections, 2,768 decontaminations.Boyd Lake: 37,871 inspections, 1,646 decontaminations.Horsetooth Lake: 35,405 inspections, 485 decontaminations.Cherry Creek Reservoir: 28,855 inspections, 832 decontaminationsCarter Lake: 20,162 inspections, 593 decontaminationsBlue Mesa Reservoir: 18,271 inspections, 625 decontaminationsEleven Mile Reservoir: 14,556 inspections, 119 decontaminationsNavajo Reservoir: 14,291 inspections, 321 decontaminationsJackson Lake: 12,519 inspections, 362 decontaminationsLake Granby: 10,988 inspections, 480 decontaminationsMcPhee Reservoir: 7,883 inspections, 306 decontaminationsFor more information, visit CPW’s aquatic nuisance species prevention website, https://bit.ly/2vjdVLk.