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News
By Vicki Browne
Iron County Lakes & Streams Partnership
Anglers on lakes and streams where spiny water fleas have invaded are likely familiar with the gelatinous blobs of fleas that amass on fishing lines and prevent a hooked catch from being reeled in. Although they are not harmful to pets or swimmers, they are a threat to the aquatic food web and a two-fold source of frustration for fishermen — fewer big fish to catch and more gummed-up lines.
Spiny water fleas are an invasive aquatic animal, a type of zooplankton (water animals usually less than two millimeters in length) that eats other zooplankton. Small prey fish also eat zooplankton, so when the spiny water fleas consume it, the smaller fish cannot thrive. Small fish cannot just switch to eating spiny water fleas because the fleas’ long tails and spines make them too difficult to digest.
Invasive species are plants, animals or other living organisms that are both not native to a location and also likely to cause economic and/or environmental harm. Since March 2019, Michigan law requires anyone operating a watercraft on a lake to make sure it is cleaned and drained before leaving a lake in order to mitigate the spread of invasive species like the spiny water flea.
Anglers and boaters are most likely aware of the importance of cleaning their watercraft and equipment before leaving a lake. Newcomers, visitors and folks taking advantage of the free fishing weekend June 10-11 may not be as well-versed in the steps they must take after a day on a lake.
Here is a brief review of the steps to take before you leave your location:
• If a boat wash is available, use it.
• Remove all mud, debris, aquatic plants and animals from watercraft, equipment and trailers.
• Drain live wells, bilges and ballast tanks.
• Pull the plug and drain all water from the boat.
• Dry everything with towels, if possible.
• Dispose of unused bait in trash receptacles only.
• Never move fish or baitfish species from one waterbody to another.
If you plan to visit another lake or waterway:
• Use hot water (120ºF) to clean live wells, bilges and equipment. Some websites recommend a 10% bleach solution, but the U.S. Fish and Wildlife Service indicates this might be harmful.
• Let the boat, trailer and equipment dry in the sun for five days.
Carefully following these steps can prevent the spread of invasive species. ‘Hitchhikers’ on boats, trailers and equipment are one of the primary ways that invasive species and fish diseases are spread from one lake to another.
Eurasian water milfoil is an invasive aquatic plant that outcompetes native milfoil species and disrupts recreational use of a lake. Jake Sawecki, a graduate research assistant at Michigan State University, hypothesizes that EWM’s dense patches allow prey fish like bluegills to hide from predator fish like largemouth bass — leading too much slower growth for the bass.
Rusty crayfish are an invasive animal species sometimes used as bait. They get introduced into lakes when bait is not disposed of properly. Rusty crayfish are voracious eaters who consume small fish, fish eggs and aquatic plants, disrupting the food web at multiple junctures.
Invasive species have detrimental effects on fishing on the lakes and streams where they have been unknowingly or heedlessly introduced. We can protect lakes by being aware of potential threats and making sure not to transport harmful organisms or diseases from one waterbody to another.
One careless act is all it takes, so clean, drain and dry your boat, trailer and equipment, and dispose of bait properly every time you go out on a lake.
A more comprehensive booklet of boating regulations is available at a sets.kalkomey.com/boater/pdfs/handbook/michigan-handbook-entire.pdf.
This year’s Free Fishing Weekend will be held June 10–11, in conjunction with Three Free weekend, during which residents and nonresidents can grab a fishing rod, ride the off-road trails and visit state parks and boating access sites — all free of charge.