Minnows dying on the bottom? Maybe the tough winter has depleted the Oxygen levels. Any suggestions ???
Northern WI. Lake Winter Oxygen levels
Starting to see more posts on the main thread about 02 level concerns as others are starting to notice also. Talked to some pretty knowledgeable guys on a Vilas county lake today that said crappies were biting right under the ice last week for them and they believe that oxygenated water weighing less is highest in the water table and fish will move there to survive. Dying weeds consume oxygen so shallow bays would be bad now. Areas with current or springs would be best. I like that advice and will adjust my approach.
I had this happen a few years back on a shallow-ish U.P. lake I love to fish. Great fishing in December and January, then around the beginning of February my minnows were dying. I had no idea what was going on. I thought I got a bunch of bad minnows or that I had them too close to the heat in my truck. But, in reality, the lake had very little oxygen. Talked with a guy that said the pike were swimming near the top trying to get oxygen. Noticed when I put the minnow down just a few feet they did ok. But, even with pike swimming higher, they weren't in the biting mood.
This winter seems like one where I would expect oxygen levels to be "ok". Ice is about normal and the snow on top isn't overly great....but, this does seem to be the time of year it happens. Need a few warmer days to get that melted snow going into the ice cracks. Just been so cold.
I have seen this in large (fertile) bodies of water as well. In particular Vieux Desert in the Northeast Bay off of Desolation Point. This can stem from weeds, lots and lots of "brown" dead weeds. In this case you will have to fish deep and usually into basins. It's harder fishing but if you find them, fish can be concentrated in an area and it can be actually easy picking.
Decreased O2 levels across the lake however can cause lethargic fishing everywhere dependent upon the lake.
Some lakes also have small partial winterkills that people are unaware of that happen. Mann lake in Vilas county is notorious for sporadic winter kills.