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Posts: 284
Location: Eagan, MN | One of my fishing partners recently said something to me in passing that has me thinking.
"Probably ninety percent of your musky catches are thermal related."
So, what did he mean by that? What do we know of the musky and thermal needs or regulation? Is there any research in this area? What about your anecdotal observations? If there is a thermal connection, how can we, as anglers, use this to our advantage?
Tell us what you know about muskies and thermal needs.
Brian |
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| Hi Brian.
I've noticed a few things over the years that might be related to this. When fishing cooler water in the spring and early summer, we find most of our fish activity in the warmest water. The same thing happens in the fall prior to turnover. If you can find a spot on the lake that's been in the sun for most of the day, even if that water is only 2 degrees warmer than everywhere else, that's where the fish seem to be.
Early to mid summer as the fish are transitioning from the shallow weedy areas to the bars and points, we've found a lot of back and forth movement, but once the surface temps get over about 72 across the board, the fish are out deeper, now presumably looking for cooler water. A buddy and I had a discussion recently about fishing rocks during the transitions during the 68 - 72 degree water period, and how a cold night can push them back into the weeds. Conversely, a hot day seems to push the weed oriented fish onto the rocks. An interesting discovery for both of us was that the very first rock-oriented fish that turn up after a cold spell during this time seem to show on on the dark colored bars and points - black rock. Our theory there is that the dark colored rock absorbs a lot of heat from the sun, effectively giving them a nice warm place to hang out.
So I think the thermal related theory holds some merit. It seems to me that water temps under 68 leave muskies looking for warmer water, and over 72 has them looking for cooler water. In between is where we see the most variety on where we're finding fish from day to day. When you find 70 degree water is often where you will find fish on all different types of structure.
That could all be related to baitfish movements, though. Maybe their food seeks out those temperatures and they just follow.
Either way, it seems to me that the range of 68-72 is what they're looking for. If the water is significantly warmer than that, they are looking for cooler water. If it's significantly cooler than that, they are looking for warmer water.
I don't know of any research to that end, but it would appear that they do have a "comfort zone"...
Edited by esoxaddict 11/7/2014 5:57 PM
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Location: Hayward, Wisconsin | On a related note, during my tracking work on Eagle Lake, I learned that the bigger fish feed mostly in deep water where Cisco's were and then went to the warmer shallow weedy bays...to digest? Likely...the water in the weedy bays was as much as 10 degrees warmer than where they were feeding on Cisco's!
During the hot month of July, the big girl I followed made a 10 mile circle from deep to shallow and back every 3 days! |
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Location: Rhinelander, Wisconsin | Interesting. Do you think we are catching those shallower muskies on Eagle as the are up digesting their last meal, and are triggering them to strike when they really have no need to eat? |
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Location: Hayward, Wisconsin | During the summer, yes Steve I believe that may be the case. Triggering them by a lure landing close by and instinct taking over or they have finished digesting and not yet left the shallows or are on the way out.
In attempting to catch them (to enable us to sedate them and pump their stomach) with a barbless single hook lure, I was never able to get one to hit in the shallows. They would follow (except for the large males) but never hit.
In the late fall when the cisco's move in to spawn, all bets are off.
Also, I found in mid September, they started moving back toward the spawning areas...closest to them that they had been all season. Two other tracking studies that I am aware of showed that females moved to the spawning areas late in the year, near to where they would spawn the following spring. |
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Location: Eagan, MN | Larry, I have a theory about those sunbathing muskies that are trying to warm themselves. I think the warming may serve a dual purpose; that is, to perhaps aid digestion and/or to prepare them for foraging. Other cold blooded animals warm themselves prior to foraging in cold water. Why not muskies? I have found that there is research about thermo regulation in fish and apparently warmer water allows fish to swim faster. Would muscles warmed in the shallow sun baked water provided an advantage to the muskies vs. cooler holding prey fish when foraging? Do they warm themselves in anticipation of this activity? While not proof of this, I have witnessed muskies feeding on open water forage very close to where they have been sunbathing, so wonder if there is a connection to warming stations and key foraging locations. Did you see any evidence of this in your tracking efforts? Do warming stations tend to be in close proximity to where they forage as I have observed? A 10 mile round trip wouldn't seem to support this BS theory.
EA, are your observations that muskies attempt to remain in their preferred temp range, as best they can, and regulate themselves accordingly by changing their location? I'm thinking Larry's tracking studies may also suggest this to some degree? The dark rock observation is very interesting. Do you find current to play into the dark rocks they use? Are they in calmer areas to help preserve the heat? Or is that not necessary?
Curious too about how seasonal water temps affect thermo regulation in muskies. They sure don't seem to have the same type of behavior relative to warming themselves in the shallows in the mid- to late-fall like they do in the summer months.
Brian
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| Larry Ramsell - 11/8/2014 9:45 AM
On a related note, during my tracking work on Eagle Lake, I learned that the bigger fish feed mostly in deep water where Cisco's were and then went to the warmer shallow weedy bays...to digest? Likely...the water in the weedy bays was as much as 10 degrees warmer than where they were feeding on Cisco's!
During the hot month of July, the big girl I followed made a 10 mile circle from deep to shallow and back every 3 days!
How are muskies tracked? A 10 mile circle is interesting.. is there some sort of electronic device attached to them like ive seen on sharks where they bolt an electronic data recorder/gps unit to their dorsal? thanks. |
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Location: Hayward, Wisconsin | BrianF: What you have stated is basically what I said with the exception of the 10 mile round trip...that trip covered several "feeding stations" and I don't think that in the warmer waters of summer that too excessive. Also, this was the largest muskie I tracked...the smaller ones didn't travel that far. However, it was probably only 4 or 5 miles in a direct line from the shallows, but the was considerable distance compared to "next to".
My suspicion is that muskies feed most in summer/hot months when digestion is much faster than fall. Yes, they "bulk-up" in the fall, but I believe that to be a factor of easy prey and slower digestion and not because they are feeding more than in the summer. Only thing I have seen slow them down in the summer...at times...is when it gets too hot. But even then they still feed to their own detriment as thermal stress does kill some in very hot weather/water. I just don't think they can help themselves in the "too hot" water and that is why many don't fish them when the water temps get over 80 degrees and the southern guides move north. |
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| BrianF. - 11/8/2014 6:00 PM
EA, are your observations that muskies attempt to remain in their preferred temp range, as best they can, and regulate themselves accordingly by changing their location? I'm thinking Larry's tracking studies may also suggest this to some degree? The dark rock observation is very interesting. Do you find current to play into the dark rocks they use? Are they in calmer areas to help preserve the heat? Or is that not necessary?
Brian
Brian, it sure seems like it. On the rocks, in the weeds, on the rocks, in the weeds, back and forth from day to day. It's happened enough times where I started looking at the previous day's/nights weather and current surface temps trying to figure out why "they were here yesterday, and today they are over there." Multiple sightings of the same fish over the course of a week confirmed my suspicions that it was the same group of fish moving in between those areas.
The black rock fish? That was something that we only noticed in the morning. As the sun got higher and the day (and surface temps) warmed up to 71, they scattered a bit.
As for current, I think that always comes into play. They are going to relate to structure based on natural current and wind induced current no matter what.
But there seems to be a direct correlation to water temperature and what areas they will be inhabiting, and why they move around in the same area over the course of several days.
A good spot is a good spot, and they're going to use it. It's just a matter of figuring out when they are likely to be moving up onto it to feed, and when they might be 30 yards away in the weeds or 30 yards out on a hump. I'm thinking water temperature plays a big role in that. |
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Location: Black Creek, WI | BrianF. - 11/8/2014 6:00 PM
Curious too about how seasonal water temps affect thermo regulation in muskies. They sure don't seem to have the same type of behavior relative to warming themselves in the shallows in the mid- to late-fall like they do in the summer months.
Brian
Post turnover the lake is generally the same temperature top to bottom. Thus, I think the need to sunbath in the summer months may be indicative of the need to travel through temperature gradients to find the food they prefer (cisco can be below the thermocline). Cold Blooded creatures need stability and even a few degrees can be significant. Thus, I'm sure they still sunbath to some extent in the cooler water periods, but probably not as intensely when a LARGE temperature gradient exists in their homeland like that found during the summer. |
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| sworrall - 11/8/2014 1:56 PM
Interesting. Do you think we are catching those shallower muskies on Eagle as the are up digesting their last meal, and are triggering them to strike when they really have no need to eat?
Steve, not sure how much you've fished Eagle, but this is what Steve Herbeck has been saying for years. "You gotta pee em off, cause they aren't eating where we are fishing."
Larry, in your study on Eagle, what was the average depth of the ciscoes and feeding muskies during the day out in the open water in July/August on relatively sum days? And then was there a "usual" time they started rising in the water column later in the day? If one were to troll the "abyss" out there on sunny days, how deep would you run the baits?
Edited by MstrMusky 11/11/2014 10:35 AM
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Location: Hayward, Wisconsin | MstrMusky: found cisco's at all depths (max basin depth was 50 feet but most was less than 33 feet). Even saw muskies feeding on them on/near the surface. During tracking, if a transmitter muskie was not moving, there was usually a school of bait nearby, otherwise they were always on the move across the abyss. They certainly didn't need to follow structure to go from point A to point B! When in the bay areas, they usually followed the 18 foot contour and deeper in the bays the 13 foot weed edge. I didn't attempt to monitor the times the cisco's came up to the surface, but they didn't have to be there to be fed on by the muskies.
Made an interesting observation one day after a severe cold front. A small weed bed that the day before had been on the surface was GONE! Actually "sunk" a few feet by the cold...and guess what? One of the transmitter fish was buried under those weeds. Fun/interesting stuff. |
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Location: Black Creek, WI | Do muskies exhibit behavioral thermoregulation? Is this what those MN Sunbathers are doing? Check this link out: http://www.earthlife.net/fish/tregulate.html
Recognizing that fish are Ectotherms tends to explain many of the fish movements that I've observed over the years. Or at least "I" think so....
http://esi.stanford.edu/temperature/temperature3.htm
The feeding aspect of muskies has been in the limelight for most anglers, however that is a pretty small window of opportunity. Thus, I've spent a good portion of my fishing experimentation around identifying other locations that muskies use the majority of the time... which in many cases is NOT related to feeding. Or, to recognize locations that they may not use for long periods of time, but makes them more vulnerable to angling (in a general sense, this usually means shallow).
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Location: Ashland WI | MstrMusky - 11/11/2014 10:34 AM
sworrall - 11/8/2014 1:56 PM
Interesting. Do you think we are catching those shallower muskies on Eagle as the are up digesting their last meal, and are triggering them to strike when they really have no need to eat?
Steve, not sure how much you've fished Eagle, but this is what Steve Herbeck has been saying for years. "You gotta pee em off, cause they aren't eating where we are fishing."
Larry, in your study on Eagle, what was the average depth of the ciscoes and feeding muskies during the day out in the open water in July/August on relatively sum days? And then was there a "usual" time they started rising in the water column later in the day? If one were to troll the "abyss" out there on sunny days, how deep would you run the baits?
The $1,000,000 question for me then is "What is the best way to tick them off?"  |
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Location: Rhinelander, Wisconsin | According to Herbie in a conversation in Herbie's Lund he and I had, he feels it's motion, and lots of it. MOVE that lure...even a sucker..and hope the Muskie plays, in Herbie's words, "Cat and mouse". The mouse stops moving, and the cat loses interest. It doesn't have to EAT the mouse, only bite it.
I have direct evidence that fish sometimes react exactly as Herbie claims (basically a strike response) on hundreds of hours of Ice video. |
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| They are programmed to eat. They are programmed to chase down their prey and make sure it doesn't get away. I spent my youth fishing clear water, watching fish of all species eat and get eaten. The one thing I noticed that stuck with me is that fish seldom eat anything that just sits there, or moves very slowly. There was a good population of bass that liked to hang out in the milfoil around the boat slips. We spent entire days digging crayfish out from the rocks and feeding those bass. What we learned was that if you drop a crayfish in the water, and they freeze, they can sink to the bottom without much attention from surrounding fish. When we dropped them in the water and they immediately swam, none of them got far.
It's the same reason that the best live bet is fresh caught. Be it shiners, suckers, dace, red tail chubs, the best bait is the bait that swims like mad trying to get away.
Translating that into musky fishing, if it's "getting away", it's getting eaten. There are times when you need to slow down and put a lure right in their faces and give them a chance to eat it. But for the most part, the second a musky senses that your lure is "getting away", it's gonna eat that lure. |
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Location: Black Creek, WI | If you believe fish are using a location for reasons OTHER than to feed... then of course your presentation may require some alterations.
Before moving on to a discussion about presentation... I'd like to further understand why fish may be using some very PREDICTABLE locations for reasons other than to feed... so I can identify more opportunities to target.
You can't catch what isn't there... so let's not rush ahead to the "P" in the In Fisherman Equation (Fish + Location + Presentation = Success). I'd like to connect F and L together.... for when a fish is NOT feeding... as the majority of their life is spent digesting, not consuming. Digesting periods are a much LARGER window than actual feeding windows. |
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Location: Eagan, MN | Jason, I prefer the modified and improved version of the In-Fish formula...F+L+P+T=S. The 'T' stands for timing. You can't catch what IS there, but not inclined to chase or eat. Seen it all too often! Fish when the fish are feeding to improve on the success formula.
Sorry for the distraction. Carry on...
Brian |
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Location: Black Creek, WI | BrianF...... agreed.
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| Here's a fun analogy on finding the fish:
A good spot is like a restaurant on a Saturday. During the "feeding windows", they're all in the restaurant eating. After that? They're still hanging around, and some will eat more just because it's there. Once they've gone home to lie on the couch, (the sunbathers) feeding time is over. There are a few that show up early, and a few that come late, so there's a time before and after "feeding time" where some are eating. While we like to think the feeding windows happen in a flash, it's more of a bell curve. You start seeing a few lazy fish, and a few more, and then they really start chasing your lures, then they start eating. And it tapers off gradually after that.
It's the time PRIOR to that that we largely ignore. The restaurant is empty, but they are starting to hang around in the parking lot. They're hungry, and they will feed. They're still relating to that structural element, they're just off it a ways. But casting into the restaurant while they're behind you in the parking lot isn't getting you a fish in the net. It's those times where I think we'd be better served to work our spots from a cast length out in deeper water, or even inside-out. They're hanging around the food, but they're not in it or on top of it yet.
Prior to the "parking lot" phase, they're on the move. They're on their way to the restaurant. If you can pinpoint the likely travel routes between the main lake basin/deep water and the "restaurant", you should contact some fish.
An interesting side note:
We've had days where nearly every fish we saw followed our lures, didn't make a turn, went under the boat and just kept right on going. We ran out of daylight before we figured out where they were going, but they were going somewhere. Spot after spot after spot, we were just pulling them off of points and bars. I don't think one turned around and went back.
Edited by esoxaddict 11/12/2014 1:36 PM
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Location: Black Creek, WI | EA,
Nice analogy. However, in some lakes... I think you have your restaurant and parking lot backwards.
In some lakes, they feed in the basin (parking lot) and lounge/digest on the couch (shallow structure).
In lakes where the basin is so massive it is almost futile to fish for the feeding muskies out there... your only option is to find structures where the basin dwelling food makes contact with structure on a regular basis.... or to learn how to catch muskies that are NOT actively feeding (target them in the parking lot).
10 years ago while fishing Lake Vermilion for the Simply Fishing Tournament... there was a group of VERY experienced Canadian Trollers staying at the same resort I was using. They trolled the lake for 10 days prior to the event... and didn't catch a single musky. I was shocked to learn this as I firmly believe that the majority of musky feeding activity occurs out in the basin on this lake. If fishing where they feed is the most productive approach... why did these guys fail so miserably? Their own assessment was that they spent too much time dragging baits too deep (below the muskies) but even after making adjustments to fish higher in the water column they never contacted a musky.
No doubt, I'd much prefer to target feeding muskies as they are the most vulnerable to angling. However, if you can't predict where they are going feed you may want to look for some other options. Thermal Considerations. |
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| Jason,
You make a very good point about those types of lakes. I will admit that other than Eagle, the other lakes I fish are typical Northern Wisconsin fisheries - less than 900 acres, small basins, and plenty of structure adjacent to what little open water basins are present. If the fish aren't in the bays in the weeds, they're out on the bars and points. If they aren't on the points and bars, you look to the humps. And open water that is lacking major structural elements you can cover with a few deep water presentations and be assured that most of the fish in the lake have seen your lures today.
My guess as to the Canadian trollers (and this is only a guess as I don't fish those types of lakes) is that whatever lures you're putting out there in the main basin of a lake like Vermilion don't come close to a size of what the fish that feed in those areas are eating. If they're out there eating lake trout, a depth raider or a 10" Jake isn't going to get their attention very often. If there are large schools of pelagic bait fish, they can basically just hang around them and eat whenever they feel like it. You're out there looking for the needle in a haystack fish that may decide to eat a lure when it's surrounded by actual food. |
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Location: Eagan, MN | Why do larger sized muskies seem more driven to get and stay warm? Some speculation I've heard/read is that warming increases metabolism, which increases speed of digestion, which increases growth rate. What is the advantage of additional growth when the musky is already, say 55", and large enough to tackle the some of the biggest forage species in the lake? Is it an increase in egg mass, which increases the chance of successful propagation of their genetics?
Even if we never know the answer to these questions, knowing that BIG fish are driven by thermo regulation is a key for us anglers, is it not?
Brian
Edited by BrianF. 11/12/2014 3:40 PM
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| BrianF. - 11/12/2014 3:39 PM
Why do larger sized muskies seem more driven to get and stay warm? Some speculation I've heard/read is that warming increases metabolism, which increases speed of digestion, which increases growth rate. What is the advantage of additional growth when the musky is already, say 55", and large enough to tackle the some of the biggest forage species in the lake? Is it an increase in egg mass, which increases the chance of successful propagation of their genetics?
Even if we never know the answer to these questions, knowing that BIG fish are driven by thermo regulation is a key for us anglers, is it not?
Brian
I'd agree that when it comes to big fish, it's likely related to egg production in the females at least. At that size, I'm not sure fueling growth applies as much as simply needing to eat and metabolize a larger volume of food. |
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Location: Hayward, Wisconsin | Brian: I too believe, as does EA, that the big girls "need" to eat more due to body size to maintain mass, but ALSO, these bigger girls produce more (and perhaps) larger eggs and need more food to that end as well. |
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| So Jason...
If the fish are feeding out in the main basin of the lake in deep water where targeting them is futile, it stands to reason that we're catching fish that just aren't hungry. What's your theory on why they are biting? Is it just a genetic response to the movement and vibration of our lures? Is it nature telling them to take advantage of a meal when one presents itself? Or perhaps they are sitting there quietly digesting their meal, and the presence of our lures is just plain annoying enough for them to want to chase them off with force if necessary?
Edited by esoxaddict 11/13/2014 1:01 PM
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Location: Black Creek, WI | Good question EA. One I've pondered for many years.
If you believe that the ONLY type of strike is one for the purpose of feeding, then TIMING is everything. You want to present a lure to a digesting fish that is reaching the end of its digestion period and preparing to go on the hunt again (leave its comfort spot). Thus, you can get a feeding strike in a NON-feeding location by being there at the right time.
However, I believe there is another type of bite. One some people call an EXCITEMENT bite. One can speculate for eternity if it truly exists or why it happens. Could be instinctive (linked to the lateral line?). Could be the predator behavior like many referencing the cat&mouse deal. I don't know. Or... when I think I've achieved an excitement bite... perhaps I just got lucky in my timing and actually got a feeding strike from a fish that was just about to vacate the area in search of its next meal? We'll never know for sure.... |
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| As I alluded to earlier, there are periods leading up to and away from active feeding windows when they will still eat. Given the opportunity to consume a meal with little energy expended, I believe that they will take that opportunity more often than not. I firmly believe that instinct plays into this with fish that are not actively feeding, and will still whack a lure just because it's there. How many times have you had a fish follow your lure from a distance, obviously not interested enough to eat it (or it would have already) that sort of hangs around watching your figure 8, and suddenly comes completely unglued when you make the right move?? That's not feeding in my opinion.
You're right, we will never know. I also suspect that there's always a few fish that simply didn't score during "feeding time". No predator is successful 100% of the time.
So back to thermal considerations... Outside of the periods of feeding, and the dead time of digesting when they won't even turn to watch a lure go by, why do you think they are seeking out certain temperatures? I can see it in the summer when the warmest water holds a lot less oxygen. But what about the rest of the time?
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Location: Black Creek, WI | EA, I think its that simple. Feeding locations... and digestion (comfort) locations. Anything in between would simply be a travel route.
Researching Thermoregulation in Ectotherms (cold blooded creatures) reveals a lot of cool stuff. Iquanas and how they feed in the ocean and "regulate" on shoreline rocks seems very similar to what I believe many basin feeding muskies are doing.
The connection to thermoregulation and digestion is due to metabolism. However, as you read up on this stuff... you'll also notice that CHANGE in temperature has negative effects on cold blooded creatures and they will relocate in an effort to slow/minimize this change.... or to recover from the change. Thus, in spring and fall when the lakes are changing in temperature most significantly... I feel muskies will do some strange things to avoid this chaos. Some anglers will struggle at these times... while others hit the jackpot. |
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Location: Ashland WI | Ok, so if we feel that muskies are feeding in the basin areas and digesting in shallows, what about shallower reservoir/flowage style lakes?
Do these fish not follow a pattern like that at all? |
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