AIS – Did You Know?

At a recent "Tuesday Group" meeting, Derrick Passe, Lake County Soil & Water Conservation District, spoke on Aquatic Invasive Species. As you may know, Derrick attends the monthly WICOLA Board Meetings and with his team updates the Board AIS efforts as well as on other Lake County SWCD projects.

At Tuesday Group Ken Wichmann, WICOLA member, asked Derrick some great questions on AIS that one may not think to ask. The following are Ken's questions with answers from Derrick.

Question; First, I recall reading about a year ago that the DNR had found spiny water fleas in the stomach of a White Fish. I had been told earlier that local small fishes could not/would not swallow the little creatures. I have heard nothing since. Has the DNR done any additional work on predation of spiny water fleas? Do White Fish really eat them? I assume (perhaps wrongly) that nature will provide an answer. Either the local fish population will learn to eat them or new species will prosper who find them palatable. What eats them in their native areas? In other contaminated USA waters?

Answer; The Spiny Water Flea (SWF) is edible, but has been shown to cause perforations of the GI tract of young perch. Concordia College identified SWF in Basswood by examining stomach contents of Tulibee. I liken the value of SWF as a food source to that of popcorn to humans, while it may look big and tasty, it is very low in nutritional value. (The spine that makes it look big is made of silica.)

An interesting occurrence relative to SWF. In some lakes, established populations have disappeared. No one knows why.

Question; An out of state marine mechanic tells me he has noted both zebra and quagga mussels routinely in the water cooling cavity of out board motors. It appears to be a problem with motors left with the lower units submerged in the water either at a dock or boat lift. This would surely distribute the critters if the boat fished multiple water bodies. Have you or your working partners noted this problem? Do you have a solution that is compatible with current decontamination machines?

Answer; As for the Decontamination stations, like the Ely Unit at the Chamber Parking Lot, I have a few comments: Attachments- can be used to flush inboard and outboard motors. Effectiveness is as good as the Decon operator. The bigger concern is ballast tanks on ski boats.