Water Temps are DANGEROUSLY High

[Mike Hulbert]

Water temps have soared the past week with very warm days and nights that are only getting down into the 70's. The water never cools off from super hot and humid days we have been experiencing.

Today water temps were 79 degrees in the morning and got up to 85 degrees by the afternoon.

My Indiana trips are over until early fall, when the water temps and oxygen levels get back to normal.

Please take it easy on these fish until water temps get back down. The Indiana DNR has built us an awesome fishery so lets do our part and take care of it during these high water temp times.

Over stressing these fish, unhooking them in the hottest part of the water column and then releasing them again in the hottest part of the water column with little or no oxygen only means one thing...dead muskies.

Lets take care of the fishery!!!

Thanks!

[steven]

Thanks for the info mike!!!
We all need to do out part!!! It won't be long when we will be fishing again for muskie.
Steve Fiorio

[rustyman]

Anyone know the temps of barbie and tippy. I didn't know if they were getting up there as well as webster.

[Billy B]

Yeah, Water temps are definitely too high to be fishing. Please take care of the fishery and leave them alone until the fall.

[Mike Hulbert]

Rustyman,

Those are the temps of Webster, Tippy and Barbee.

Steve and Billy, thanks for being on board and doing your part to protect the fishery!!!

[Dave T]

How come your not in minnesota yet??

thought you bolted north as soon as school lets out...

Dave

[Mike Hulbert]

Several reasons Dave if you must know.

1. Had to renew my teaching licence with a few Graduate classes.
2. Business was good in Indiana with the recent mentioning of my guide service in In-Fisherman Magazine
3. Fishing was good here in Indiana
4. Water temps were lower than normal here in June so I was able to fish
5. Trips in the Metro were a little slow, I know...it's hard to believe that a guide would actually say that business was down!!! LOL

I normally do head north in early June, but this year several things kept me in Indiana longer than usual. I'll be up there very soon to put a hurt on those big Minnesota Muskies!!!!! You big spotted monsters better be ready!!!!

[Juhas]

Come on! We know why you really stayed around longer. Mike's in LUV

[DCates]

I posted this on another board and didn't receive much response:

Here in Indiana surface water temperatures are approaching or have hit (depending upon whose water temperature guage you use) the 80 degree mark. There is much discussion about preserving the fishery by not fishing for them until temps go down to below the 80 degree mark. Excuse my "duh" moment, but is there any scientific data with regards to water temps and C&R success?

Can anyone point me to any peer reviewed studies on this topic?

[Mike Hulbert]

Dave,

I will look for info for you.

Trust me it is real and should be a concern to people.

There are also TWO different types of "Hot Water" which most people who don't buy the "hot water kills fish" theory don't really understand.

Here in Indiana our lakes are very small and warm up very quickly. The warm water penetrates the water column ALOT faster than they do in northern lakes found in Wisconsin and Minnesota. Oxygen levels go down, and the thermocline sets up. There is really no usuable oxygen below the thermocline. So, say the thermocline is at 15 ft. Well here in Indiana our water temps will be at 85 surface and 80 degrees 15 ft. down. Muskies can't survive with the stress of being caugh and fough in water that is very warm, with very little oxygen, then released back into the hottest part of the water column.

Lake in Mn, Wi and Canada hit 80 degrees from time to time, yet after a cool night they are back down to 75, 73, etc... Our waters don't ever really cool down, so the pentration is deep in the water column.

I have been out with Jed Pearson, our head DNR biogiest and did an oxygen study with him. We also looked at water temps at 1 ft. all the way down to 16 ft.....water temps were above 80 and almost no oxygen present anywhere....the weed kill doesn't help this either....I then went out with my oxygen senson and temperature guage along with my aqua view with John Bette from Stealth Tackle. We saw many fish with signs of being caught laying on the bottom dead.

When I was younger and didn't know any better, I killed a few in my day by fishing in hot water. Fins were gushing blood, gills were really pale in color, etc...put the fish back in the water...and belly up she went.

Trust me it is true and legit. Why do guides in Kentucky, Illinois, Indiana head north for the summer months? So they don't kill muskies. Tony Grant who guides in Kentucky told me about a 50+ that died last week before it even hit the net. He is already in Wisconsin, but one of his friends told him about it. Gregg Thomas will tell you the same, as will Chad Cain who has a degree is fisheries biology. High water temps kill muskies.

Doesn't muskies Inc still run an ad that shows a dead musky and says something about high water temps kill fish????

It all has to do with the high water temps, the penetration of the warm water, little oxygen in the water and being released back in the hottest part of the water column.

I know Steve Fiorio who lives on the Barbee Chain has seen a few dead muskies floating after trying to be released in hot water.

I'll see what other info I can find. If any of you have anything to add, please do so.

Thanks,

[tomcat]

I do not have scientific proof at my finger tips as i type this, but i have personally killed 3 or 4 muskies years ago fishing when the water was over 80.

I have also been bass fishing on indiana lakes with my kids and watched people catch a muskies and they would not release when water temps were high. these are all my personal experiences.

[DCates]

I am not arguing the hypothesis, but would prefer a scientific basis rather than a peta-esque feel good warm and fuzzy answer. Cold water holds more oxygen than warm water, which is in line with temperature/oxygen sensor data. My suspicion is that there is a combination of factors at work here (temperature, metabolism rates, genetics, dissolved oxygen content, water quality - including the added chemicals from a weed kill, boating pressure, prey condition and availability all come to mind).

Rereading this, I am not critical of anyone here, nor am I critical of the concept. I just would like to see some research (I am so much of a musky nut that I would stay up at night reading it!).

[muskihntr]

I’ve taken a lot of “heat” in the past on this topic, so I have been a little reluctant to post my feelings. With that said, I can back what Mike stated about what we have done and saw in the past with both temp/oxy sensors, as well as an aquavu camera. It is true without scientific evidence we have nothing to really go on but I think common sense has to come into play at some point. These fish in Indiana have a very small comfort zone in the summer, where there is safe oxygen levels and cool enough water temps. However they still gotta eat and they will. We have seen this by some cheap investing in a temp/oxy sensor and aquavu camera. Dnr reports in the past have also showed that the oxygen levels below 15 feet on these lakes drops off fast to minimal levels. Just because they swim away doesn’t necessarily mean they are not going to become turtle food at some point if they cannot recover well enough. Can we prove it? Well no, however we saw enough on camera to know that there are more dead fish than we know on the bottom of the lakes. We saw enough during 2 days of doing this to use common sense to know we should back off fishing in the summer down here. There is a huge difference in 80 degree water temps in Indiana vs. the northern regions of Wisc, Minn, etc. Our nights do not cool down near as much and those lakes (in general) seem to be able to sustain lower water temps at higher depths as well as higher oxygen levels unless they get extended periods of extreme heat.

Disclaimer: This is my personal opinion………….
To me it comes down to taking care of what we have, lets not look at this with blinders on, if there is a chance it might be hurting the fishery by fishing in high temps, why not just lay off til it cools down? Even at night the temps are not cooling down that much so I don’t see that as being a good choice either. Again, just my personal opinion. While people will argue that Indiana is stocked heavy because it is considered a put and take fishery, we should keep in the back of our mind what has happened over in Ohio. If I am not mistaken the state is considering axing the Musky program all together. It can happen that quick. We all need to set aside our differences and take care of what we have because nobody knows how long it will last. We can all work together to make sure we have an awesome fishery for years to come.

[muskihntr]

Oh i almost forgot.

Yes Juhas!

[Ifishtolive]

Hey guys I for one know how bad we want to fish, after several years and sometime well spent in Mike's boat, I finally got two fish in the boat. The one I have yet to post the picture of, and one I got a buddy of mine on his first time fishing for them, and the first spot we stopped on. He caught a 39 on the first 10 casts!! So now I'm pumped!! But I will patiently wait, work on baits and get the kids back on big blue gills, and spend time reading my electronics for this fall!! Taking care of the fishery is most important!!

Buddy Ellenburg

Take a kid fishing they'll have a lifetime of memories!

[crittergitter]

Here is some science we dug up last year over at SOMA(Musky Inc#56). It's an extremely harsh way for a fish to die. Not much different than if you threw it up on the bank.

Muskie Fishing In Extreme Conditions
By Brad Waldera and Tom Betka


There are certain fishing conditions that require special precautions to be taken, or that extra care be given to the fish in order to reduce overstressing Muskies, and help minimize the occurrence of delayed mortality. The information contained in this article may help you in making a decision that could ensure that less fish die from delayed mortality.

Muskie fishermen release the majority of the fish that they catch. Because of this, there are certain steps we should be taking to ensure that we’re releasing fish healthy, and in good condition. This article will try to explain how taking special precautions in various fishing situations can greatly increase the survival rate of the Muskies we release back into the lake.

Two of the main topics summarized in this article are lactic acidosis, a buildup of lactic acid that can cause abnormal heart rhythms (potentially leading to a sudden stoppage of the heart), and hypoxemia, which is a condition of an abnormally low blood oxygen level. These two issues account for a significant portion of the delayed mortality following the catch & release process. Fishermen can have some control over these issues by simply being more aware of their effects on Muskies, and by changing some of the ways in which we fish for them.

Lactic Acid is a natural by-product of functioning muscle tissue. When fish have normal blood oxygen levels, their muscles can function aerobically with very little lactic acid produced. When the supply of oxygen in their blood is depleted, more and more lactic acid is produced and they may experience numerous metabolic abnormalities. This condition is further worsened by the hypoxemia resulting from a prolonged fight in water low in dissolved oxygen, or from long periods of air exposure while the fish is handled and photographed.

Hypoxia means low oxygen, and refers here to a fish’s lack of obtaining adequate oxygen. This lack of oxygen causes their pH level to decrease and they become more acidic. That in turn leads to the interference of oxygen getting delivered to the tissues, such as the heart. As the heart becomes hypoxemic, it becomes more susceptible to abnormal rhythms. In periods of pronounced hypoxemia, the heart may even cease to function normally, possibly resulting in the death of the fish.

Many Muskie fishermen believe in using stout tackle and fighting the fish quickly without over-stressing the animal. When fighting a fish on the line, lactic acid begins to build in their muscle tissue. The longer the fight lasts, the higher the level of lactic acid produced. Once the level of lactic acid reaches the “point of no return”, it may cause the fish to die. They may swim away at the time they’re released, but can often die many hours later.

Higher water temperatures can magnify the oxygen and pH imbalance in the fish, and this increases the importance of shortening the fight. To reduce lactic acid levels and restore the normal pH of the blood, exhausted fish need oxygen fast, and the only way to get oxygen to the fish quickly is by allowing water to flow through its gills. Therefore many fishermen are now choosing to simply unhook the fish in the net, to avoid handling them at all. Unhooking and releasing Muskies in a timely manner will allow them to recover much sooner, and could mean the difference between life and death for the fish.

As most anglers know, water temperature is the main factor in determining how much oxygen is available to the fish. Because warm water isn’t capable of holding as much dissolved oxygen as cold water, lakes with low oxygen levels can also increase the occurrence of hypoxemia in angled fish, potentially increasing delayed mortality. Many serious Muskie fishermen will not fish for Muskies at all once the water reaches certain temperatures, such as 80 degrees. In the warm summer months when water temperatures are highest, many Muskie anglers choose to pursue other species of fish that are less sensitive than Muskies to the effects of low dissolved oxygen levels.

Fishing in high winds can also increase the risk of delayed mortality, especially if you’re fishing alone. It may be quite difficult to control the boat while playing the fish, which can prolong the fight time and increase the occurrence of lactic acidosis. Concurrently, if the water temperature is high, the fish may also become hypoxemic. Fishermen should strongly consider whether they should fish these locations in these scenarios or choose a different approach.

As Muskie fishermen, we have a great deal of control over many of the factors affecting delayed mortality, simply by limiting the amount of time we keep a fish out of the water. While the incidence of delayed mortality has been estimated to be in the range of 5-30% the exact figure can never be known, as there are many determining factors. Therefore we recommend that every effort be made to keep delayed mortality deaths to a minimum.

There are many other situations that also require taking precautions to help minimize the risk of delayed mortality, such as targeting deep-water fish. To achieve neutral buoyancy and have the ability to stay at any depth it may want to, a Muskie has to be able to take gas into the bladder and let gas out of it. When fish are rapidly brought to the surface from deep water, they may experience a rupture of the swim bladder, possibly allowing a gas bubble to enter the bloodstream. This gas bubble could then find its way to the gills, brain, (or other vital organ) and thus block vital blood flow from the downstream tissue. This type of injury is similar to that seen in humans who rapidly ascend from deep water. In addition, if the fish is caught from water deeper than about 50 feet, it may experience decompression sickness, (the bends), just like humans do. Due to these concerns, it has been suggested that Muskie fishermen avoid pursuing deep-water fish if they intend to release them.

Certain care should also be taken to ensure the release of healthy fish when fishing at night. In many instances the water temperature will be more beneficial to the well being of the fish in the cooler evening hours, but there are other issues that come up. You’ll want to make sure you’re aware of the location of your release tools and also minimize the amount of time the fish is in the net.

Cold air temperatures may also have a slight effect on the Muskie. When taken from the water in very cold air temperatures, there is a risk of freezing to the fish’s eyes and/or gills. Some consider it to be a concern, but at this point it doesn’t seem to be a big issue.

As much as we enjoy fishing for Muskies, there are times throughout the year when it can prove detrimental to their survival for us to fish for them without first considering the scenarios we’re faced with that particular day. If certain steps are taken, we can ensure that Muskies will survive and prosper for the next generation of fishermen.






A special thank you goes out to Tom Betka for his advice and assistance with this project. It was well appreciated.

References
Thomas Betka, MD, BS (Aquatic Biology)
Medical Director, Hyperbaric Medicine & Wound Care, Aurora Baycare Medical Center, Green Bay, Wisconsin



Casselman, S. J. 2005. Catch-and-release angling: a review with guidelines for proper fish handling practices. Fish & Wildlife Branch. Ontario Ministry of Natural Resources. Peterborough, Ontario. 26 p

[Pool]

Just booked a room at the lodge so I can fish for Crappies all weekend.

[DCates]

crittergitter and all:

Google the Casselman study for some interesting information. I am aware of Waldera's and Betka's research, and look forward to the Carleton University study results (water temperature only being one consideration there).

[jkahler]

Why doesn't the DNR close the musky season in the summer?

[crittergitter]

Ok Dcates, I just found and read the Casselman article on catch and release. A LOT of good stuff in that article. In the section titled Physiological affects he does talk about what a fish goes through.

To summise; they get an excess build up of lactic acid in the muscles due to exersion. Then, when taken out of the water their gills lose the abillity to transer gases for a period of time. Therefore, the fish gets an increase of CO2 and a decrease of O2. Without O2 the fish can not reverse the affects of the lactic acid build up. Then, the fish is placed back into water with an 80 degree surface temp.....that has little to no dissolved oxygen for the fish. So, it still can not recover. The fish has to be able to retreat to an area of the water column that does have enough dissolved oxygen so it can reverse the acid build up. Also, due to the temperature difference from the surface down to the thermocline the fish could experience of level of shock especially after having gone through the other stresses to it's physiology. Add it all up and the chances for mortality start increasing during the hot water priod. It is sound science to me. Though, a more comprehensive study on this would be very beneficial to the fishing community.

[steven]

SO to put it simple:::::
DON"T FISH FOR MUSKIES WHEN WATER TEMPS GET HOT!!!!!!!
VERY SIMPLE!!!
I for one love these muskie waters being great and want to keep them that way!!
See u when the water temp comes down.
Steve Fiorio

[muskiefool]

I commend you for pulling the pin in the high temperature periods Mike, the fish and the future of your business and those who expect to maintain the fishery will enjoy it and appreciate it down the road.

I think any of us can look back on things that happen to fish when the temps get up there and say with certainty that those effects are negative no matter if its in your aquarium at home or in the bait bucket or live well.

I'll give you 2 examples about high temps changing the way fish are regulated, in MN there is no Muskie Tournament permits issued during these times due to past disasters that had a tremendous effect on the fishery.

In MN also any Walleye tournaments conducted in these high temp periods are mandated to be Catch and Kill due to high mortality.

Any biologist worth his salt will tell you there is increased mortality during hot water periods whether they support Peta or not I'm not sure.

Not everyone cares or understands mortality factors and how to adjust their fishing to preserve the fishery, some just want to fish for better or worse and they'll stock more.

We were just encouraged in the latest Muskies Mag to use our infrastructure as a tool so that may be a good place for you to start your search for info; Tom Betka or any DNR biologist, although you may be looking for Muskie research alone to confirm these issues as fact that will be very difficult if not impossible to to attain; as I was told by senior biologists when I was doing research for my C&R information, mortality factors are the same for all fish, a fish is a fish.

Here are some peer reviewed study's directly linking high water temps to mortality.

We have to decide whats more important, The fish or the Angler; the angler will be there if the fish is available, if the fish go so goes the anglers; I'm pretty sure that's what Gill had in mind when he called it Muskies Inc and not Muskie Anglers Inc.

http://afsjournals.org/doi/abs/10.1577/1548-8675(1996)016%3C0364%3AWASMAW%3E2.3.CO%3B2?prevSea rch=&searchHistoryKey=

http://afsjournals.org/doi/abs/10.1577/M04-106.1

[Cold Front]

Seems amazing to me that this topic even requires any discussion. Your fishery is a synthetic one, it takes huge resources and an incredible amount of time to create it. WHY ISN'T THE SEASON CLOSED DURING THIS PART OF THE YEAR ... Here in MN we enjoy some incredible fishing have both natural and manmade opportunities and we close our season to protect our resources. It's nuts that people need to be told and retold and retold. This discussion comes up on this board every season it's a wonder you guys ever got a fishery going.

[Halfpint]

No closed season would ever pass in Indiana. The DNR puts them in there for a reason...to catch. That's not my thinking, that's theirs. And although the closed season would save some fish, their phillosophy has always been "it's worked pretty swell so far, so why change it". Maybe in the end we ballance out the high fish mortality in the summer by stocking 5 fish an acre...who knows.

Either way, there are lots of times in the summer when the temps aren't near 80 degrees in the Webster area lakes...sometimes for weeks at at time :) No need to close the season when you can fish in conditions that are reasonably safe for the muskies. And if someone says I can't fish when the temps in the hotest part of the day are UNDER 80 degrees...