Just recently, I caught my first juvenile rainbow trout on the middle Bow River, in Cochrane. The number of captured juvenile brown trout is increasing , as the water levels drop, over the past few days. During my fly fishing survey on the Bow River this summer, at first it looked pretty gloomy, but now things are starting to pick up and the fishery doesn’t look as bad as I first thought. The big news is that there was a successful hatch of rainbow trout eggs last year, on the Jumpingpound Creek. The brown trout hatch on Bighill Creek was also successful. The reason I can tell you this is that both the brown trout and rainbow trout fingerlings are about the same size.
The trout above is the rainbow trout that I recently caught recently, on the Bow River in Cochrane. It is one of a few that I hooked this past week. The small trout came out of the Jumpingpound Creek, after spending its first year in the creek. Good water levels in the JP this year, cause a delay in the normal migration patterns of the trout. They usually come down out of the JP Creek in the first part of July. However, it was nice just to see that there was a successful hatch last year.
This brown trout was one of many caught in the Bow River, but the trout was most likely hatched on the Bighill Creek last year, from the 2017 fall spawning season. All of the trout seem to be in pretty good condition, which is very important for their winter survival this year. This is good news for the local fly fishers in our area, without small trout being injected into the river every year, your trout population would collapse.
These days, when I catch a small rainbow trout on the river, I will pause to wonder if the trout in my hand is carrying the disease resistant genome for whirling disease. After following the topic of whirling disease quite closely over the past few years, I am confident that a disease resistance is the only hope for our Jumpingpound Creek strain of rainbow trout, and those strains further downstream.
Stonefly Recovery Happening
This year there is a definite increase in the number of stoneflies present in this reach of the Bow River. The stonefly has been pretty scarse in recent years and this may have something to do with the big flood of 2013. because the Ghost Reservoir is on the upstream side of this reach of the Bow River, the recruitment of stoneflies on the river would take a little longer than on a normal stream, with no dams.
A few days ago, while fly fishing the Bow River just a few blocks away from my house, I notice lots of summer stoneflies along the water’s edge. The stoneflies were Acroneuria sp., which are a late summer perlidae hatch that happens on the Bow River. This is why I call it the summer stonefly. The stonefly population is of primary importance for all of our wild trout, in this reach of the Bow River. Later on in the open water season, the fluctuating water levels in the river have a huge negative impact on other invertebrate hatches. The stoneflies are able to migrate into deeper water during these water level changes, but other insects can’t.
With healthy stonefly populations, the trout should benefit from this food source and increase in numbers. It is a wait and see theory, but any sign of hope is good enough to keep my interest high, during the wild trout’s journey to recovery. I do recall a time when insect hatches along this reach of the Bow River were a lot more prolific. Nowadays, you just don’t see the midge and mayfly hatches of yesteryear.
A few years ago, the water levels in the Ghost Reservoir were brought up to maximum levels after the run-off season was over, now they keep the Ghost reservoir levels down well into the summer. This must have made an impact on the tailwater fishery that we had. However, this is only speculation at this point in time.
More Habitat Growing Along the Creeks
This is the 6th year of the “Bow Valley Riparian Recovery and Enhancement Program” and the results are getting more obvious these days! New native willows and trees are starting to provide great instream habitat and stream bank stability. A sign that our efforts have not been in vain. Willows are growing on both sides of the stream channel now and it will only get better as the years progress on!
Above: This photo of Bighill Creek shows how a good planting program can enhance the wild trout habitat and improve stream bank stability. Note the planting on the farside of the stream bank was carried out on an eroding slope, five years earlier. Now the erosion site is stable and covered with native willows. Some stream banks are more difficult to plant on, but persistance pays off, over time.
New Issue of Stream Tender Magazine
I have just uploaded the summer 2019 issue of “Stream Tender Magazine” at: http://magazine.streamtender.com . Please check it out.