Go Back   Alberta Outdoorsmen Forum > Main Category > Fly-Fishing Discussion

Reply
 
Thread Tools Display Modes
  #1  
Old 05-26-2022, 01:25 PM
orvisman's Avatar
orvisman orvisman is offline
 
Join Date: Sep 2016
Posts: 62
Default Salmonflies in Decline?

Good day.
I was fishing prairie creek yesterday. It was a bit slow, but still a good time. Met a couple of other anglers and had a quick chat. Also, I turned over some rocks and did some kicking and netting. Most of the stoneflies I came across were golden, but the odd salmonfly was found in the mix. I have heard and read that this stream used to have great salmonfly hatches many years ago. Does anyone know what happened? Why have the populations declined?
Thanks

Last edited by orvisman; 05-26-2022 at 01:33 PM.
Reply With Quote
  #2  
Old 05-26-2022, 05:34 PM
Don Andersen Don Andersen is offline
 
Join Date: Dec 2007
Location: Central Alberta
Posts: 1,794
Default

Quote:
Originally Posted by orvisman View Post
Good day.
I was fishing prairie creek yesterday. It was a bit slow, but still a good time. Met a couple of other anglers and had a quick chat. Also, I turned over some rocks and did some kicking and netting. Most of the stoneflies I came across were golden, but the odd salmonfly was found in the mix. I have heard and read that this stream used to have great salmonfly hatches many years ago. Does anyone know what happened? Why have the populations declined?
Thanks
Insect eaters decline as insects.
https://www.canada.ca/en/environment...pulations.html

Don
Reply With Quote
  #3  
Old 05-26-2022, 06:14 PM
Lornce's Avatar
Lornce Lornce is offline
 
Join Date: Mar 2010
Location: Calgary
Posts: 2,663
Default

During the 70's when I first moved here, there were massive spring hatches of not only Salmonflies but Squalas and march browns in the spring—followed by a good variety of mayflies, etc. There has been a slow decline in streamside insect life ever since. Some of my old haunts north of Calgary have suffered from the drought and other factors to the point where it is hard to find much under rocks.
__________________
Often I have been exhausted on trout streams, uncomfortable, wet, cold, briar scarred, sunburned, mosquito bitten,
but never, with a fly rod in my hand have I been in a place that was less than beautiful.

My blog - casting on the waters

fishing regulations and facts on fish handling
Fishing Regulations
Reply With Quote
  #4  
Old 05-27-2022, 08:23 AM
Sundancefisher's Avatar
Sundancefisher Sundancefisher is offline
 
Join Date: Jan 2008
Location: Calgary Perchdance
Posts: 18,775
Default

Quote:
Originally Posted by Lornce View Post
During the 70's when I first moved here, there were massive spring hatches of not only Salmonflies but Squalas and march browns in the spring—followed by a good variety of mayflies, etc. There has been a slow decline in streamside insect life ever since. Some of my old haunts north of Calgary have suffered from the drought and other factors to the point where it is hard to find much under rocks.
Critical discussion

As reports continue to continue to come in from anglers who say the numbers of rainbows in the Bow is declining. It has me wondering what the impacts of reduced phosphorus in Alberta streams would have on trout populations.

I would postulate that phosphorus inflow is not significant in the mountain and foothill streams and rivers and that it may be more of a closed system.

We have evidence based upon experience of sewage inflow into both the Bow River and the Crowsnest River that the eutrophication caused by phosphorus dramatically increased bug populations and thereby dramatically increased the trout and fish carrying capacity of those rivers.

Since the elimination of nutrient release due to improved sewage treatment technology, the side affect has been the negative consequences in the slow decline on fish populations on sport fishing. The Bow and Crowsnest Rivers have been a major tourist draw for years and the decline in the fishery will eventually impact tourism. At the same time the local pressure continues to build on all water bodies.

When examining some key facts we can see that in a closed system or limited nutrient renewal system that removing nutrients over time will compromise the carry capacity of the stream or river.

I personally reviewed hundreds and hundreds of historic F&W reports in my past job roles and the fact is our foothills and mountain streams historically contained not only more fish but larger fish. There are photos of streams harvested of very large bull trout, and streams so full of spawning mountain whitefish that it looked like you could walk across their backs and keep your feet dry. We don’t see this anymore. One could say it’s a result of fishing regulations and fishing pressure but maybe it’s a deeper issue. Maybe if harvest was stopped completely that those rivers may take thousands of years to recover due to nutrient limitations.

The historic harvest of all this fish biomass as well as continued harvest since has likely reduced the phosphorus in the rivers and streams enough to significantly limit not only population recovery but also the maximum carry capacity. How much phosphorus is interesting. Some reports on perch for instance shows 1% of weight is in phosphorus. For trout is is likely similar so over time has more phosphorus be removed that comes into the system? Do we know? Do we care? Can we imperially or scientifically prove that this isn’t significant?

We have seen that populations in the Bow are falling hard… and phosphorus inflow is low and available phosphorus from past sewage diacharge may of been flushed from the system due to successive floods. As a result we see a reduction in eutrophication of these systems.

In this day and age… is adding nutrients to streams and rivers even possible as society seems to feel its taboo to mess with nature? At the same time can it be considered correcting an imbalance caused by people, so to inoculate our rivers and streams with nutrients to replace over a hundred year is the best thing to do.

Let’s face it. Angling pressure is climbing. Native streams and rivers are limited in Alberta. Our waters along the mountains and foothills are glacier and spring fed and aren’t productive like a prairie river.

It may take some strong leadership in Alberta to understand this and consider some research.

I think it is worth a discussion.
__________________
It is not the most intellectual of the species that survives; it is not the strongest that survives; but the species that survives is the one that is able best to adapt and adjust to the changing environment in which it finds itself. Charles Darwin
Reply With Quote
  #5  
Old 05-27-2022, 08:33 AM
Don Andersen Don Andersen is offline
 
Join Date: Dec 2007
Location: Central Alberta
Posts: 1,794
Default

Pollution is good!
The Crowsnest is a perfect example. As each sewage pond was closed with the effluent moved to the plant @ Frank the bug life fell.
Finally got to the point, I didn’t bother going there any longer as the Crow had finally reached the productivity it was when i lived in Pincher Creed I fished it in 1967/68/69.
Was a shame.

Don
Reply With Quote
  #6  
Old 05-27-2022, 10:43 AM
Sundancefisher's Avatar
Sundancefisher Sundancefisher is offline
 
Join Date: Jan 2008
Location: Calgary Perchdance
Posts: 18,775
Default

Quote:
Originally Posted by Don Andersen View Post
Pollution is good!
The Crowsnest is a perfect example. As each sewage pond was closed with the effluent moved to the plant @ Frank the bug life fell.
Finally got to the point, I didn’t bother going there any longer as the Crow had finally reached the productivity it was when i lived in Pincher Creed I fished it in 1967/68/69.
Was a shame.

Don
When I electrofished the Crowsnest it was extremely apparent where the sewage game in.

Green rocks and tons of bugs below, bare rocks and far fewer bugs above. Lots of fish below.. far fewer above.

I see there is some political correctness in people’s thinking on this.

Part of what I hear is the term sewage and pollution used however fundamentally it comes down to phosphorus and nitrogen. If we talk in those terms it may take away the mindset of sewage and cleanliness and health aspects of the potential solutions.

I know some has been done such as adding oats to Elbow Lake to improve productivity and improve brook trout sizes. In that instance I feel brookies are like perch and can over populate and stunt which negates benefits of improved food production.

A lot of foothill stream got stripped of bug life if the big floods. Likely taking out silt and nutrients with it… making these streams and rivers even less able to sustain fish populations.
__________________
It is not the most intellectual of the species that survives; it is not the strongest that survives; but the species that survives is the one that is able best to adapt and adjust to the changing environment in which it finds itself. Charles Darwin

Last edited by Sundancefisher; 05-27-2022 at 10:49 AM.
Reply With Quote
  #7  
Old 05-27-2022, 03:23 PM
Lornce's Avatar
Lornce Lornce is offline
 
Join Date: Mar 2010
Location: Calgary
Posts: 2,663
Default

For the Bow, there was a massive silt discharge years ago and replacement of bankside vegetation with rip-rap (flood mitigation they say). The Trans Alta water Diversion in the summer/fall of 2011. It would be foolish to believe that there would be no negative impacts to the aquatic environment, from the millions of cubic meters of silt, coating the Bow rivers stream bed and extended high, turbid flow rates, post runoff. Sapro growth also deteriorated conditions.

What Trans Alta diversion did with the huge silt deposit was have a terrible effect in not only choking out spawning areas but also affecting insect cycles. Areas that were clear pebble bottom or compact were choked with inches of silt. I really did notice a huge difference in the number of nymphs and their resulting hatches after that point. There were dramatically fewer Stones, BTO's, and a cross-section of others in traditional areas where I would normally be able to see them flipping stones and studying bug seigning. The Net Builders disappeared as did many of the larger stones. With the lessening of a food source and then the hit of sapro on the Trout it was a perfect storm. As far as Whitefish go I look at them as the canary in the coal mine. They are indicators of the quality of a river as they rely on fairly pristine conditions to survive. The whitefish population is declining.

Years ago hatches were so high you had to be careful to keep your mouth closed for fear of swallowing stoneflies mayflies and caddis.
__________________
Often I have been exhausted on trout streams, uncomfortable, wet, cold, briar scarred, sunburned, mosquito bitten,
but never, with a fly rod in my hand have I been in a place that was less than beautiful.

My blog - casting on the waters

fishing regulations and facts on fish handling
Fishing Regulations
Reply With Quote
  #8  
Old 05-28-2022, 01:14 PM
Don Andersen Don Andersen is offline
 
Join Date: Dec 2007
Location: Central Alberta
Posts: 1,794
Default

Tried enriching three ponds at Nordegg with rolled oats to improve bug life. Worked for a while.

Don
Reply With Quote
  #9  
Old 05-29-2022, 10:14 PM
thumper's Avatar
thumper thumper is offline
 
Join Date: May 2007
Location: Canmore
Posts: 4,740
Default

Before the sewage treatment plants in Lake Louise and Banff were modernized, fishing the Bow River below Banff was great! And not only for the fish - lots of Bald eagles, mergansers and high winter counts for Goldeneyes and other invertebrate eaters. Canmore had the highest Christmas bird count in all of North America for American dippers. Brown trout had come up all the way to Bow Falls in Banff! No longer.
__________________
The world is changed by your action, not by your opinion.
Reply With Quote
  #10  
Old 06-01-2022, 07:39 AM
ecsuplander ecsuplander is offline
 
Join Date: Oct 2008
Posts: 133
Default

Don you said "worked for awhile". What happened in the long term?
Reply With Quote
  #11  
Old 06-01-2022, 10:42 PM
Don Andersen Don Andersen is offline
 
Join Date: Dec 2007
Location: Central Alberta
Posts: 1,794
Default

Quote:
Originally Posted by ecsuplander View Post
Don you said "worked for awhile". What happened in the long term?
Slight flows over time reduced nutrient load. Water returned to previous levels.

That is the advantage of sewage, the nutrient load stays constant varying only due to flow conditions,


Don
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 12:25 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.