Why trout need cold water

Jonny Armstrong, [email protected]. Click photos to see a full-size version. Right click and save image to download. Skip to main content. Toggle menu Go to search page. Search Field. Warm water has overlooked importance for cold-water fish, like salmon and trout, study finds. March 25, Story By:. Contact Info Grab a feed of news and stories for your site. A stream thermometer is a very useful tool when it comes to fishing for trout. It could tell you where the fish are holding, how they are feeding and when you should probably switch from a freestone fishery to a tailwater fishery.

Over the years, I have set up many packs and vests for trout fishing. When I began fishing I never thought I needed to know about water temperature or carry a thermometer. Now, I have one on every rig I own. They are fairly inexpensive and provide great value. If you are fishing a stream that gets warm and forget your stream thermometer, get in an elevated position and watch the trout in the run.

If they are holding in one place opening and closing their mouths, they are stressed. As water temperature rises, the amount of dissolved oxygen in the water decreases. Likewise, as the water temperature decreases, the amount of dissolved oxygen increases.

This seems simple, right? But at what temperature should fishing be curbed to ensure trout survival? The actual temperature varies from species to species. Brook Trout need more oxygen a lower water temperature then rainbows or browns. This is why most brook trout streams are usually located at higher elevations.

Studies vary on the overall lethal water temperature that will cause a Brook Trout to die. It stands to reason that a fish, one which is already oxygen stressed while positioned carefully in current that minimizes its energy use, will be dramatically more stressed after being hooked and attempting to fight its way to freedom. In fact, in many cases, a fish otherwise properly handled and released under thermally stressful conditions may be likely to not survive.

So how do you know when the conditions remain comfortable enough to fish your target stream without creating a lethal situation for its residents? Unfortunately, studies vary and there doesn't seem to be any one set of accepted limits. Of course these are merely guidelines. Water temperature is not the only determining factor of dissolved oxygen speed of current also plays a factor, for example.

Trout which spend extended periods of time living on these generally accepted thermal margins will likely have a greater tolerance outside these margins. On days when temperatures soar, and especially during extended periods of high temperatures, the catch and release fisherman should pay specific attention to stream temperatures throughout the stream he or she is hoping to fish.

The King River NE Victoria Whitfield is 4degrees cooler than most trout streams in the north east as it comes out of Lake William HovellHowever,last year after 8 days in a row above 40,fish floated.

Sad to see. The King Valley Tourism Assoc. Well for the last 40 years on my home waters, I use the 70 deg rule as the brick wall in my trout fishing, the last few years, I been using 65 deg as the limit, due to both water temps and water levels! During the Dog days I also discovered that there are plenty of carp to be fished for fresh water bonefish along with large mouth bass and inshore salt water!

It don't just has to be trout fishing during these warm summer spells! When to over night lows hover in the mid 's plan on fishing for other types of fish! Oh and the carp is a great primer for fall steel head and salmon on the great lakes! I do a lot of my scouting for the coming deer season that starts in Sept with archery!

Trout bums like myself needs some venison too- and well the hides go to the tanner and a lot of my friends gets good deer hair for well Trout Flies! We have a rule in Sweden that we go home if the temperature is above The fish can't take the stress above that. I wonder if the trout move upstream when water warms?

In other words, do they migrate seasonally? In a stream I often fish, the water got low, warmed up to 78 deg. I walked the banks and could see into nearly every hole, down to the bottom and not one trout to be seen. I especially looked for very slow moving fish, sheltered on the bottom or in the shade but saw none.

Needless to say, I didn't bother fishing. Upstream about 4 miles I would imagine the water's much colder, as it's closer to the source tall mountains with melting snow. At some point, all of us have to make a strategic retreat. Not to overdo the military analogy Words: Todd Tanner.