Sean landsmans study Noble Beast is a good one, If it has been over 80 for a long time that is pretty brutal.. I can't imagine fishing the way the temps have been in the last month almost..
Most of the SW lakes were 85+ That could put stress on any fish caught not just musky. It's no wonder all the pike were dying in some of the shallower lakes
I can't speak for the st. clair people as ive never fished it, but it is a massive body of water, and the water column takes A LOT longer to warm up than the inland lakes.
Maybe some of the guys fishing st. clair can help out, but the inland lakes are probably all around 80 degrees 10-15+ ft down by now, and St clair, probably isn't bad at all.
I would think St. Clair is still plenty fishable and if you handle fish properly, by keeping the fish in the net etc.. then holding them for a few secs for a pic then fish would most likely be fine
Most of the charter guys out on st clair prob would never stop fishing regardless of temps. Im sure other guys who fish out there constantly can give a little insight here
Drastic surface temp changes, don't affect the lower water column as much. We were just in canada and the temps would rise from 73 in the morning and 82 during the day. Fishing was brutal tough, but the fish were just as active early morning as they were when it was 80 degree's
The trollers especially are hard on the fish in LSC when its this hot. Just the sheer number of fish they catch is going to cause a few to have problems, plus the fights are typically longer and they often just net the fish and lay them on the bottom of the boat. The big aerated livewells help save a lot of fish but sadly not everyone has them on board. The thing with LSC though is the water coming through the channels is a lot cooler then parts of the main lake. It can be in the 80s in some areas and 73-75 in others. Fish the cooler water if you are worried about it. At least there are soo many fish in LSC that the lake can rebound from losing a few to bad releases.
As for the exact water temperature to stop fishing? You aren't gonna find that study anywhere. It would be a difficult study to perform, would require a lot of costs and a temendous time involvement(Muskies are kinda hard to catch for most of us). Not to mention a lake and its muskies would basically have to be sacrificed to do it right. Plus if you did a catch and release mortality study in hot water on just one lake people would poke holes in it and claim it didn't apply to all waters. The landsman study proved that catch and release doesn't kill many fish if done in water under 78 degrees but clearly fishing in warmer water is a problem. I draw the line at 80, I think thats a good stopping point. Some guys will fish in low 80s and have their ways of justifying it but for me when it hits 80 I'm done.
AS far as the science goes, I have been trying to find tables to show you, but its really hard to get something with the right specifics, and every lake is completely different with different amounts of hardness, forms of algae, and weedgrowth. So basically every lake is a little different, but the basic Idea is this:
Water holds oxygen, obviously, and as the water temp increases the max amount of dissolved oxygen it can hold decreases.
The major variables here are the type of system. Swanzey mentioned the size of St Clair, but something else to add to that is that there is a constant flow coming in from Lake Huron… The things that add dissolved oxygen are current, and cooler temps, meaning that from the get go St Clair will have more acceptable water for fish than the average inland lake that will get to the point of stagnant in hot temps. If the water is not moving, just because the temp of water will hold the right amount of oxygen, doesn't mean it is. Not to mention that high water temp further down (in Murray I have seen 80 in 15 fow or more) means even less O2.
This could also mean that on occasion on St Clair, fishing the massive weed flats would be dangerous, but fishing around the edges of the channels and at river mouths could still be OK.
But like someone mentioned to me before, temps definitely hurt the fish, and as much fun as it is catching them, is it worth catching a monster and killing her???
This is always a good topic so I will throw my 485 cents worth at it.
When I was working at the PNNL out west I worked on a temperature/exposure study for smolts in the Snake River. Different fish but the science cross-applies and I of course got the chance to pick the brains of many different biologists and fisheries guys while there. I cant post the actual charts or materials because it was paid for by the Idaho Power Company and is there property. However I will paraphrase-
There are two concerns with heat, max temp and time of exposure. The latter being the more damaging of the two. Since I was the Bottom feeder of the group I got to watch and monitor the tanks while the temps was increased to determine time of LOE (Loss of Equilibrium) when the fish turn sideways or upside down and time of death.
The difference in TOD between 76 degrees and 78 degrees is exponentially different. The fish can recover with temporary exposure (hitting a bait and then being released to cooler water) but cannot when they are exhausted and then oxygen starved (Long fight, bottom of boat, Out of water etc…) Back to the point. Fish would die in ~ 35 minutes at 76 but ~10 minutes at 78 so the change is drastic.
I will not discuss stress of fight poor handling etc… we all know that.
It has to do with oxygen debt and the circulatory system of a fish. They have a circulatory system that is primarily capillary based and lack a large arterial or veinous system that allows for rapid transport of oxygenated blood to the deprived muscles. Imagine running ten flights of stairs, then hold your breath, then try to breathe with a towel shoved in your mouth…oh and you smoke three packs a day.
It takes a long time for a fish to circulate the highly oxygenated blood to to the deprived area under the best of conditions heat makes it worse.
What some dont know is what exactly does heat do? How does it kill?
Heat causes the denaturing of proteins, all proteins have a specific shape and are held together by chemical bonds some of which are weak and can be broken by excess heat. That is why fish change their temperature based on metabolic need, warmer to digest (like an enzyme lowers the amount of energy required to break down and harvest energy) cooler to slow it down and reduce the amount of oxygen needed to survive.
So denaturing explained 101: When you cook an egg the white part is all protein, it is clear in its correct form and fluid once cooked it cant go back. Think of nerve tissue and other proteins as cooking egg whites the higher the heat the faster it turns into a non usable "cooked" form. Put an egg at room temp for two hours and back in the fridge its fine, leave it in the yard from Easter til memorial day and well many of you know how that goes…
So for me Im done at 75 no excuses-
Next week we will discuss how oxygen sole purpose is to be a high energy electron acceptor in the Krebs cycle…enjoy!
Kevin
Fished solo LSC last weekend casting the cooler deeper water and fished mostly late day to late night. I spent Sat, Sun and Mon out there and took some time during day scouting open water spots. Counted 6 floaters on Sunday and another 2 on Monday. There was a MOMC tourney last weekend too. The main lake surface temp was anywhere from 75-81 up to 18-19 feet deep. Channels with decent current were anywhere from 74-76 surface temps. The fish I caught took awhile to recoop but it was all channel fish and I did have another issue with a 48"er that took a long time to go down. All fish were netted quickly and released fast but I still noticed a bit of longer recoop time. My concern again is deeper fish having issues regulating their swim bladder when coming up to surface so fast from deeper water. This doesn't seem to be an issue in fall or cooler temps in deep water but I'm noticing fish seem to be more "bloated" in the summer months when caught deep. Is it depth specific or depth and warmer water temps combined? The smaller fish seem to have no issues and I just water release them but the upper 40's fish and bigger seem to be more "bloated" and I'm not speaking about girth, thickness or fat. It's been awhile since I've been out but I would assume the only real safe areas to fish on LSC is the cooler channel water.
Trollers are not going to back the boat down much, with the extended fight the smaller fish getting dragged doesn't help. They might clear some rods on bigger fish but if they slow down their baits will end up in the grass…..The bloating thing is weird, seen that happen a few times. Really does help to water release fish if they are not hooked bad and if it's not rough, it helps alot…LSC can cool down to safe temps over night.
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