Bow River Trout Populations May Be In Decline

[Vitalshok]

Where are the bugs that is a great question this year seems to be very little lately saw barely any Caddis last night.I agree with post above.

[monger]

As the city gets bigger, the quantity of low quality run-off water and the load of undesirable chemicals in the sewage system is ever increasing. These chemicals are causing genetic changes to the fish and the invertebrates. These changes are then passed down to the next generation. As time rolls forward it will be interesting to see how the trout handle these stresses along with all the angler related issues.

[toolman]

Year after year, AEP spends it's resources doing Angler surveys, fish counts, reviews of fishing regulations and continually say they are "monitoring the situation closely", yet, year after year fish populations continue to decline. All of the focus remains on C&R fisherman. We continue to look in the wrong direction to identify all of the reasons for the decline. 

There can only be as many fish as the system can support. Degradation of the habitat leads to degradation of bio mass. So, what are the stressor's that are contributing to habitat degradation?.   

That's where AEP needs to put their resources and leave us fisherman alone. We are not the problem. Our impact is miniscule in the big picture. Yet the discussion keeps going round and round us, like we all have "whirling" disease. There is no other user group that collectively, contributes more too the Bow fishery's well being, then C&R flyfisherman.

Maybe I should just write a letter to that Suzuki fellow out on the left coast and ask him to come too Calgary with his camera crew to point out the obvious to the government.

 

   

[troutlover]

On 6/14/2018 at 11:06 PM, fishteck said:

The Bow is unique in many ways, but most importantly there is not a trout river anywhere that has a city the size of Calgary as an intrical  part of its lifeline.

I"m not mentioning this to say you are wrong only to say there might be information that we can use from other trout waters that face the same population and user base as the Bow river.Yes the Bow river is very unique as it flows through a metro area of over 1 million people. There are only 3 trout streams in the world that flow through a metro area of over 1 million people  1.The Bow river in Calgary Alberta pop. 1,500,000.  2.The Chattahoochee River in Atlanta Georgia pop. 6,000,000  3.The Isar River in Munich Germany pop. city 1,500,00 metro area 6,000,000.   We might be able to learn some things from the management of these other rivers.

[Dangus]

On 2018-06-20 at 1:19 PM, BurningChrome said:

 

Surprised nobody mentioned this yet. Over the years the treatment plants have gotten "cleaner" by not pumping as much phosphate into the river, which means less fertilizer for river flora. Less flora probably means fewer bugs...

I was sort of joking, sort of serious.

here is the history of the upgrades. Last I see Is 1980 for phosphates.  I suppose it could have taken a couple decades to trickle down. Who knows...

 

 

 

http://www.calgary.ca/UEP/Water/Pages/Water-and-wastewater-systems/Wastewater-system/A-History-of-Wastewater-Treatment.aspx

[trailhead]

I am a vintage guy and I can remember at various times in the 80's and 90's people talking about how the trout population was in decline, then there was a survey done and the number I seem to recall was 2500 fish per linear mile of river. Don't know if that is the case anymore. From what I understand water treatment people come from around the world to check out our facilities and the Bow. I have never heard the Chatahoochie or the Isar called "blue ribbon" waters. and I have seen the Isar, didn't even think it had trout in it. I have also seen the Danube in Budapest and it has trout in it too.

[fishteck]

 

All this talk about AEP conducting fish population surveys, creel surveys and monitoring the quality of the water in the Bow River is just not true!

The last true fish population survey was conducted in 2007 and that represented the fish population on the Policeman's to McKinnon's stretch of the Bow. - not the entire river from Harvie Passage to Carseland. What ever the data showed at the time, the true Blue Ribbon Bow River trout population was probably half what was reported. If any fish population enhancement programs are put in place by AEP, how could we see if there was in fact an enhancement in fish population if the baseline data is questionable. The first thing to do is to get the baseline fish population data.

The last creel survey on the Bow River was conducted in 2005 and showed less than one trout being caught per hour across the entire stretch on the Bow River. All this talk about routinely catching 20 - 30 fish days is just a figment of ones imagination. There are probably 4x anglers on the river nowadays with an increase in drift and jet boat use from probably 50 in 2005 to well over 200 today, The creel survey data also indicated that the Bow River fishing pressure was the highest  of any river in Alberta. AEP is conducting another creel survey this year that will show an alarming increase in angler pressure and a decrease in catch rates.

Calgary's water treatment plants have decreased the phosphate levels in the river. AEP conducts ongoing monitoring of phosphate levels and with their modeling programs indicate that the current water treatment facilities will meet regional population increases for some time. What is surprising is the lack of data collection for invertebrate  population changes during the same time as the phosphate levels have been reduced. I have asked AEP to gather what information is available. What I expect to see is a need to do more research.

The Bow River water management initiatives that are now in place and in its simplest form will see higher flows in the early spring when reservoirs are exempted in anticipation of spring runoff flooding. Starting in mid June, flows will decrease to fill upstream reservoirs to normal operating levels and by the middle of July when flows will hopefully be stable. Increase storage capacity will hopefully increase flows through August and September. All sounds very good for the fishery, but unfortunately daily changes in dam discharge can see 15 cms change in flow per hour. We have seen 100 cms / day increases and decreases this year that could impact invertebrate survival. Discussions between the water operators and the government will hopefully see some improvement in operating procedures in the best interests of the fishery.

What does all this tell us? The common thread in this topic has been government and NGO's need to make changes to accommodate the fishing pressure that now exists. No one has commented on the fact that the Bow River fishing resource is overfished. We need to face this reality and address it now before the fishery reaches a level of no return.

[trailhead]

I guess the sky really is falling

 

[Dangus]

Sorry, I’m not clear.  Are you saying it’s a fact that the bow is overfished?

[monger]

Bron...it is your skillful fault...please take up golf

[Dangus]

38 minutes ago, monger said:

Bron...it is your skillful fault...please take up golf

But...but...I hate golf

[toolman]

On 19/06/2018 at 8:14 PM, monger said:

You guys forgot one factor that has been a rapidly growing pressure on the fish population.....large, white fish vacuuming birds with big hooks on the ends of their bills. The pelicans didn't show up on the river until mid 70's. Since then the population has exploded. Seeing flights of 50 of the buggers head upstream for the "evening float and dip" makes me shudder to think how many fish that move into the shallows in the evening are disappearing.

But they only eat suckers.......right. Check out these wounds

Yes, the American white pelican... Let's do some counting.

They consume 2kg/ day = 60kg / month x four months = 240 kg. per bird, before they head south. There's a flock of 32 pelican's circling overhead of me right now. 32x240 kg.= 7680 kg. (19,500 lbs), of fish. Only one pod. (apparently that's what they're called)

That's a lot fish and only one of many pods, (15-20?), on the Bow and their numbers appear to be increasing every year. If you do the math, you may conclude, that maybe a cull is long overdue. What do you think? Or should we just keep counting trout until there's none left?

 

[FraserN]

Very good point, toolman. The big birds are starting to show up in the NW stretch, as well. There has always been Osprey's here, taking their fair share of fish (mostly whitefish and suckers). I have even had them fly over and wait for a trout to be released by me in the shallows. They are clever birds, that are very efficient at catching fish, but are likely no where near as destructive to the fish populations as pelicans are, I suspect.

[1961flyman]

Pelicans have increased greatly in my fishing life.

From nothing to huge Flocks.

They are an invasive species which should be culled.

Starting right now !

5 Years in a row of killing every Pelican on the Bow would be a good start.

NDP surely wouldn't have the fortitude to do it.

 

 

[krk]

Actually the American Pelican is not an invasive species.  Most of Alberta is in its migration / breeding range.

https://www.allaboutbirds.org/guide/American_White_Pelican/overview

[1961flyman]

I grew up on the Banks of the Bow River.

First sighting was about 1975.

Maybe go and give one a hug..KRK..

 

[Dangus]

4 minutes ago, 1961flyman said:

I grew up on the Banks of the Bow River.

First sighting was about 1975.

Maybe go and give one a hug..KRK..

 

Apparently, They were documented in Alberta in the late 1700’s. Gonna go out on a limb here and say that they’ve been on the bow for longer. That being said, it may have become more popular for them as the fishery blew up after the sewage injections.

[1961flyman]

All I can say is based upon MY observation.

They were not here at the time.

I had already spent 15 ish years fishing the Bow by the Mid 70's..Calgary to Carsland.

No Pelicans..

Still..

I have been on the river 15 days this year..

Watching them push the fish into the shallows and then gorging on the fish is alarming.

I wouldn't mind open season on them..

Just Saying.. If it was legal I would bring my AR-15

[krk]

4 hours ago, 1961flyman said:

I grew up on the Banks of the Bow River.

First sighting was about 1975.

Maybe go and give one a hug..KRK..

 

You missed the bit about Alexander Mackenzie documenting them in northern Alberta in 1789.  They are less invasive than the Browns and the Rainbows.

[monger]

Pelicans showed up on the river down by Carseland in the mid-70's. Before that time there was none "on the river" above the weir. One July day we saw them riding thermals way up above Legacy Island.....strange to see "snow geese" in the summer. Then they slowly circled down until we could see they were pelicans. No one had ever seen them before. They figured out the Bow was a great place to fish.

I know some breed at Newell. I am not sure where these local birds breed....but they seem to be very good at multiplying. 

Migrating birds just found a new habitat to exploit

[Dangus]

Just a tidbit I came across...

“Pelicans feed on a wide range of fish and aquatic animals; sticklebacks, perch, northern pike, lake whitefish, salamanders, frogs, and aquatic invertebrates are the usual fare. Contrary to popular belief, pelicans do not consume large quantities of game fish.”

 

 

[toolman]

Let's have a look at the menu you listed, which is probably from the AEP website. It lists the food that inhabits lakes and "gamefish" on the lakes would mean Walleye, Lake trout. Fish that live too deep for the Pelican's to reach. Everything else, as the menu shows, is dinner.         

So let's assume that they're probably eating the food that's in the Bow river including, dace, sculpins, rainbows, browns, whitefish, white suckers, ling cod, pike, baby ducks, whatever they can ambush .....  

The Pelican's varied diet clearly shows that they are opportunistic feeders, They're not going to selectively "not eat" the rainbows and brown trout. That would be a ridiculous assumption. As mongers photos show, they will eat whatever will fit down they're throat. And when they fly south too the Gulf of Mexico for the winter, they will eat whatever they can find when they get there, too.

 

[monger]

I will tell the 20" rainbow I watched a pelican eat last week that it shouldn't worry...pelicans don't eat game fish....ya right

I wonder why you see all the pelicans that are hunting right in the spots where there is good dry fly fishing....maybe they know where the trout are in the shallows.

Historically the pelicans are lake dwellers, but the Bow river pelicans are not following the text books. They can eat huge fish well over 5lb. No trout in the Bow is safe

[Dangus]

the “20 inch rainbow” story reminds me a little of the “hey we got lots of snow and it was cold” story as it relates to global warming. 

Don’t get mad at me. Just something I came across.  I too, wondered how much those things have to eat to maintain that mass.  

Further reading reveals that the pelican populations were crushed and they are finally starting to rebound.  May account for your 70’s observations.

I did notice that the power lines  flossed a few around mac last year.   So the bow has that going for it. Ha

 

[BurningChrome]

3 hours ago, Bron said:

the “20 inch rainbow” story reminds me a little of the “hey we got lots of snow and it was cold” story as it relates to global warming. 

This whole thread reminds me of the "plural of anecdote is not data" saying.