BOISE — Idaho inspectors this year found more boats fouled with invasive zebra or quagga mussels than they did last year.
They spotted 48 mussel-fouled watercraft through Oct. 13, up from 35 a year ago. The number of inspections totaled 112,500, about 15% fewer than the previous year.
Zebra and Quagga mussels rapidly multiply and clog municipal water systems and irrigation pipes, pumps and canals, and pose health risks.
They are not found in the Columbia Basin. Personnel at stations in the Northwest and western Canada work together to inspect boats headed for that region.
Idaho has 20 roadside inspection stations and five roving crews. Hours of operation were increased this year. The ISDA also samples and monitors water bodies.
“We are seeing quite a bit of mussel-fouled boat movement, and other Western states are seeing the same trend,” said Nic Zurfluh, Invasive Species Coordination and Outreach Section manager at the Idaho State Department of Agriculture.
Many of the boats carrying zebra or quagga mussels continue to originate from the lower Colorado River drainage and Great Lakes region where the mussels are present, he said.
Drought likely has had some impact on the statistics.
Zurfluh said in the lower Colorado Basin, such as at Lake Powell, “the lower water levels they are seeing now exposes a lot of shoreline, and therefore more mussel beds, so you’re more likely to get them attached to a boat, or within a live well or other compartment.”
Boating activity was strong last year as more people pursued outdoor recreation amid COVID-19 restrictions.
Crews can inspect, clean and decontaminate watercraft even after roadside stations close for the season. The owner can make arrangements to meet at a state Department of Agriculture office or another site. Cost is covered by federal grants, the state general fund and the annual invasive species sticker program.
Zurfluh said fall is an opportune time for these sessions in preparation for next year, or for independent cleaning of equipment still used in fall. Cleaning, draining and drying boats and boat components, small watercraft, waders, decoys and other gear can help stop the spread of mussels.
“They are doing their part to protect areas they like to hunt or fish, or to protect ag infrastructure,” he said.