Boaters Learn About Invasive Species
By Joe Wilkinson
Boaters around Iowa know a little more about unwelcome visitors in lakes and streams, after a rain-shortened Memorial Day weekend.
At selected boat ramps across the state, 19 DNR fisheries workers fanned out to inspect boats, trailers and to talk with boaters about invasive species that can cause serious problems in those bodies of water.
“I’m looking for any aquatic plant on the boat or trailer; maybe the wheel wells, on the motor here, even inside the boat; anywhere on the boat, that they might be,” explained Nick Rhinehart, as he inspected a fishing boat coming out of Lake Macbride; one of dozens he checked through the holiday weekend.
Rhinehart was part of the DNR’s ‘ Clean, Drain and Dry’ push; to educate boaters and check for aquatic invasive species; which inhabit some lakes, rivers and ponds…and could spread to others, unless properly cleaned and disposed of by boaters. In addition to the voluntary inspection, boaters were asked several questions about the invasives, and where they boat through the season.
The push is a reminder, leading up to July 1, when it becomes illegal to transport any aquatic plants on water related equipment. Boaters must drain all water before leaving a water body and must keep drain plugs open during transport. It is illegal already, to introduce any live fish, except for hooked bait, into public waters.
At Macbride, for instance, single strands of curlyleaf pondweed are now reaching seven or eight feet from the bottom of bays in the 900 acre lake to the surface. By midsummer, those infestations will be mats of thick vegetation, without treatment. Also late this summer, pockets of brittle naiad will develop and spread.
Bass fisherman Dale Richey of Swishier understands the need for inspections, but admits being somewhat ambivalent.
“A good weed line is a nice place to fish. It provides shelter for the fish. I don’t know about which species is beneficial to the lake or not, but they do inspect the heck out of em up in Minnesota, when I go up there.”
For many introduced species in a body of water, it comes down to too much of a good thing.
“Those invasive species take over. They provide too much cover,” explains Kim Bogenschutz, DNR aquatic invasive species program coordinator. “Depending on the depth and sunlight reaching them, they become too dense. Bluegill, for instance, have so much escape cover that bass (their natural predator) can’t find them. That results in stunted growth among the larger numbers of bluegills, competing for the same food source.”
Bogenschutz notes, too, that too much vegetation can lead to fluctuations of dissolved oxygen levels, in a body of water.
Boaters can assist in the push to knock back or prevent introduction of invasive species by inspecting their craft’s propeller, underside, live wells and trailer, before they ‘put in’ for the day…or as they pull the boat out. By cleaning plant matter, aquatic animals and mud…draining water from the boat…and drying it for several days; the chance of it infesting the next lake or stream you enter will be minimized.