Fishing equipment and spreading spiny water flea: What’s the highest risk?
Researchers are making significant progress toward developing best practices for cleaning recreational equipment to prevent the spread of spiny water flea. An initial analysis of data from last summer’s field work shows that during the daytime, fishing lines gather a lot of spiny water flea. During twilight hours, when spiny water fleas are moving up the water column to feed, live wells also appear to be ensnaring a lot of animals.
To study this, researchers simulated the use of fishing equipment on Island Lake Reservoir. Each simulation was designed to replicate slow trolling. During each simulation, they used three stationary anchors, three towed fishing lines (monofilament, braided, and fluorocarbon), a towed downrigger with steel cable and monofilament line, a towed bait bucket, and a simulated live well. They also used plankton nets to determine the ambient density of spiny water fleas in the lake.
“By comparing pieces of gear to each other and to the ambient density, we can determine which items, at which times of day, are most risky for spreading spiny water fleas,” said Dr. Donn Branstrator, lead researcher on the project.
“It’s commonly believed that human recreational activity is the primary vector of spread for spiny water flea, but little is known about the specific pathways they take,” added Dr. Valerie Brady, co-researcher. “Through this research, we hope to be able to draw attention to specific pieces of equipment that should be the focus of cleaning efforts so we can minimize the risk of spreading spiny water flea to any new lakes.”
Going forward, similar field work will be conducted this summer on Lake Mille Lacs. Final results from this project are expected in summer 2019.
Spiny water flea are a small freshwater zooplankton that invades lakes and can take over the bottom of the food chain. They can decimate populations of Daphnia and other native zooplankton, resulting in a decreased food source for native fish and an increase in algal blooms. They can also clog the eyelets of fishing rods, causing problems for recreationalists. They have been confirmed in 35-40 lakes in Minnesota. Drying equipment for at least six hours is the most effective way of preventing spread.
Learn more about this research on our website.