Round 3 – 12 Aug 2014

Winner Matt Gordeneer asked…In Michigan, many lake associations are making the attempt to turn lakes into swimming pools. In the attempt, they are spraying and spreading weed killer. What effect does this have on the bass in the lake and how do you fish for them after they spray?

Scott Pellegrin answered…I’d like to start out by saying I researched for answers to your question for a few hours now. I even went as far as calling and speaking with Matt Coffaro who is a fisheries biologist in Milwaukee, WI. On the web I never really did find any info pertaining to how aquatic weed killers affect the angler and fish locations specificity. But, Matt did have some very good insight to the question.
Fish are always moving and adapting to their environment whether the reason is natural or man made. Matt Caffaro said “the fish in any given body of water are always going to go the next best available habitat.” In the case of weeds and then killing of those weeds be it by nature or man the fish will relocate to the nest best available habitat be it other weeds, docks, rock, wood and so on. What that means for us as anglers is we must also relocate.
Things I’ve personally seen are this. Weeds come and go. Some live longer in a year than others. Some years they grow deeper than other years. In the case of aquatic weed killer I’ve seen where most of the weeds are gone but some are still in place. Talk about a hot spot for bass! Weed clumps at times have been good to me. In the end we as anglers need to keep adapting if we hope to overcome the challenges man and nature throw at us.
Thanks for the question!

Pat Schlapper answered…Hello Matt, Great question. This is an ongoing problem in Northern Wisconsin also. There are several lakes that I have personally seen dramatic changes in over the past few years. It is unfortunate that a few people who happen to own cabins/houses on lakes can control so many things that effect everyone who uses and enjoys them. I can somewhat understand lakes being treated that are effected by invasive species of weeds. However, when invasive weeds are “treated” all of the native vegetation also suffers. I could give several specific examples of when and where this has happened. In any case, your question asks how if effects bass and how to adjust your tactics. When a lakes weed environment is all but decimated, fish will naturally look for the next best available type of cover. Often times it could be wood, rock, or docks. Like Scott said, even if a lake is heavily treated with chemicals to kill it’s weeds sometimes there are some that survive. If that’s the case, these isolated patches of weeds often times hold the most and biggest bass in the lake. Another factor to take into consideration when searching for bass whose habitats have been destroyed is the depth in which they live. If a lake previously had a large population of fish that lived in relatively shallow water due to weed concentrations, they may now have to retreat to deeper water to find sufficient cover. This is an unfortunate problem we all have to face in the fishing world. Hopefully this helps you out a little.

Brandon Palaniuk answered…Hey Matt, I haven’t had to experience this yet in Michigan but I believe the fish will react somewhat similar around the country. Generally the fish won’t completely vacate the area. Any living grass left will usually hold fish. Also, many times they will spray for one specific type of grass and not kill the other types mixed in. If they kill it all the fish may just move to a little deeper grass for a week or so and move back in. I’ve seen where they have sprayed and killed grass mats around lily pads where I was catching fish punching and when the mats left I thought the fish left but all they did was sit closer to the bottom and tight to the lily pad roots that were still healthy!


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