Slush under the ice. What causes it?

I'm sure this isn't that rare, but I do have to say this is the first time I came across this. I was out at Port Bolster on the weekend and after drilling through the ice, there was a thick layer of slush probably a foot or more thick floating underneath. I used a spud back down the hole to try to clear it out, but it was still tough fishing. Lures had a hard time making it through and only if they were heavy, transducer wouldn't work, and it was tough pulling the fish back up through it. Anyone know what causes this, and how long does it tend to stay around? Every hole I drilled over a 1km span seemed to have this problem, so it was impacting a large area.

Sounds like things are melting.

i had the same issue a few weeks ago, pretty much had to clear the hole after every fish. I ended up using my Kdrill on reverse and blow the hole down a few times and that kept the hole open for the livescope... until I caught a fish and that would bring a small amount of slush back each time but not complaining too much when you are catching 12 to 15" inch perch

The slush occurs because the weight of the snow sinks the ice when there is thin ice and lots of snow. Then, if it gets cold enough for long enough, the top layer of slush under the ice freezes at the top first. If it stays cold, as we would hope, all the slush freezes and we get a top layer of white ice with the black below it.

We had the same thing on Sunday out of Port Bolster. Had a narrow trenching spade with us that was over 4' long and kept sloshing that down the hole right to the handle then dipping out the slush with a scoop. Took 5 to 10 minutes of that to clear the hole, then when you brought a fish up it would stir up more slush (like what happened to Laternman75) that needed to be cleared. Later on we went out 2-3 km's out past where everyone was fishing and none of it. Came back in later on just north of the cluster of huts and got back into it again.

Been ice fishing for 45 years and have never seen anything like that.

personally, I think that stuff got blown in under the ice some time ago when there was still open water further north and now it's been stuck at specific locations only, other it should be everywhere in that area,

this one has nothing to do wit warmer temps or melting snow/weight

just my opinion and it's a pita if you sit down on it for sure

port bolster had this issue this year, it was like that since first ice. i guess its just the first time the ice froze it didnt fully freeze and is stuck under the main ice for the rest of the season, best to just find another spot to drill, or deal with slush the whole day

I Believe that is what it's from just blown in ice from it trying to freeze and opening up again several times.

It's not the first time it's happened in this area.

I’ve never experienced or heard of this ‘under the ice’ slush, but I have to agree with Shank on the cause. It does surprise me that it doesn’t just melt under there, with the water obviously being too warm to freeze. Strange phenomenon

ha. I had exactly the same issue yesterday off Port Bolster. My auger with a Milwaukee drill plus CLAM adapter/plate went all the way in (the CLAM plate literally touched the ice), and the auger just barely cleared hole at the bottom of ice. At first I couldn't get my lure down the hole, and also the same thing happened with me: My fishfinder won't read any depth. I then had to drill off some ice around the hole so the CLAM plate can get down a bit lower to clear out the hole at bottom of ice.

And then around noon when the bite was a bit slow I was trying to drill a hole about 30 yard away from where I was fishing, but this time I simply couldn't clear the bottom of the hole at all. The lure could not go down. So I gave up. And in the end I didn't move but fished the same hole all day!:-)

I guess I misunderstood the OP. I thought he was talking about slush in between 2 layers of ice. That happens often IMO

I thought I was the only one experiencing this problem on Saturday in PB

I believe this is the cause. I only ever experienced this on Lake Erie about 10 years ago. It was brutal. Kept moving further out until we found a clearing. Haven't ice fished Erie since.

i had that problem at port bolster last week when i came home i taped a skinney piece of woodabout 3 feet long to my skimmer now i just shove it down the hole and bring all the slush up no problem

I guess if I had my auger extension with me, the problem would be more or less solved. But yes, I also had the problem with more slush coming up the hole each time I landed a fish especially a jumbo perch...