Why trout in the summer ( july and august) ????

[Chaz]

In 50 years of trout fishing I've come to learn when and where to fish for trout during the summer. The wild trout streams in PA are wild trout streams for a reason. They stay cold all year. Having said that I still carry a thermometer with me because streams can spike, especially if there's been rain. I consider NC streams off limits right now because those streams have taken a nose dive since May. Up until 2 weeks ago they were still cool, but the hot weather has by now changed that.

 

[RivDiv521]

Interesting comments regarding stream temps. The majority of my trout fishing is in the Delaware River and I often wonder how useful the temperatures reported by the USGS are. I presume their reading is at a single point and only tells me the temperature at that point. One only has to get in the water and wade from shore into deeper water to realize that the river is not a uniform temperature and the gradient can be significant.

My point is that trout are not going to sit in water that is stressing them when they have cooler water available. Just sit on the Junction Pool (confluence of the West and East branches of the Delaware) some evening and watch the surface activity. If you took the temperature on the East Branch side it may be nearly 80 degrees but the West Branch side will be in the low 60's or high 50's. If you didn't know better one might take the water temp on the East Branch side of the river and conclude that they should not fish.

I would like to read the study that Mike references. I.ll bet it was done in a very controlled environment with hatchery fish that were forced to stay in the stressful water for various lengths of time.

 

[salmonoid]

RivDiv521 wrote:
Interesting comments regarding stream temps. The majority of my trout fishing is in the Delaware River and I often wonder how useful the temperatures reported by the USGS are. I presume their reading is at a single point and only tells me the temperature at that point. One only has to get in the water and wade from shore into deeper water to realize that the river is not a uniform temperature and the gradient can be significant.

My point is that trout are not going to sit in water that is stressing them when they have cooler water available. Just sit on the Junction Pool (confluence of the West and East branches of the Delaware) some evening and watch the surface activity. If you took the temperature on the East Branch side it may be nearly 80 degrees but the West Branch side will be in the low 60's or high 50's. If you didn't know better one might take the water temp on the East Branch side of the river and conclude that they should not fish.

I would like to read the study that Mike references. I.ll bet it was done in a very controlled environment with hatchery fish that were forced to stay in the stressful water for various lengths of time.

I'd like to read the study too - see post #42. Still waiting for a link to it.

Temperature gradient in a stream is generally pretty uniform, except for the types of situations you describe, where two branches come together.

 

[afishinado]

RivDiv521 wrote:
Interesting comments regarding stream temps. The majority of my trout fishing is in the Delaware River and I often wonder how useful the temperatures reported by the USGS are. I presume their reading is at a single point and only tells me the temperature at that point. One only has to get in the water and wade from shore into deeper water to realize that the river is not a uniform temperature and the gradient can be significant.

My point is that trout are not going to sit in water that is stressing them when they have cooler water available. Just sit on the Junction Pool (confluence of the West and East branches of the Delaware) some evening and watch the surface activity. If you took the temperature on the East Branch side it may be nearly 80 degrees but the West Branch side will be in the low 60's or high 50's. If you didn't know better one might take the water temp on the East Branch side of the river and conclude that they should not fish.

I would like to read the study that Mike references. I.ll bet it was done in a very controlled environment with hatchery fish that were forced to stay in the stressful water for various lengths of time.

The water temp remains constant regardless of the depth in a river or stream since the currents mix the water.

Here is a post from Mike explaining it in more detail:

Deep holes in streams and most rivers vs temperature

A common misconception expressed here and elsewhere is that deep holes present refuge for trout during warm water conditions in streams and rivers. This is not the case. The water circulates enough such that it does not stratify as it does in lakes and even some farm ponds. Thus, water temp is the same or nearly the same top to bottom. For instance, in the Delaware R in Phila where the water is 40 ft deep, the summer temp difference from surface to bottom is 0.1-0.2 degrees C. In streams you will not find a difference unless there is a spring in the hole or perhaps a density current created by an incoming trib adjacent to the hole. You may find some temp differences from surface to bottom on river impoundments, depending on flow, and perhaps a near 100 ft hole like the one on the Delaware at Narrowsburg, NY may stratify, but that would be an unusual case.

 

[RivDiv521]

Looks like my Delaware experience was due to groundwater/spring influence as there are no trips in the pool in question. I must have inadvertently found a cold water refuge.

I seem to recall reading somewhere that Harry Darby would wet wade during the summer months just so he could locate cold water pools.

 

[afishinado]

RivDiv521 wrote:
Looks like my Delaware experience was due to groundwater/spring influence as there are no trips in the pool in question. I must have inadvertently found a cold water refuge.

I seem to recall reading somewhere that Harry Darby would wet wade during the summer months just so he could locate cold water pools.

RD5

No doubt there are spring fed areas in the D. The bows have survived well over 100 years by taking advantage of the cold water areas in the River along with some of the colder tribs.