Bow River Trout Populations May Be In Decline

[fishteck]

The attached article on the Bow River Trout Foundation website will give the background on trout population monitoring for the past 30 years together with a recent retrospective data analysis that suggests the rainbow trout population is in decline and if remedial fishery management actions are not taken, the decline may continue.

Alberta Environment & Parks have started an engagement process that will hopefully see some movement on the part of fishery managers  to stop the decline.

https://bowrivertrout.org/2018/06/13/the-state-of-the-bow-river-fishery-trout-populations-may-be-in-decline/

 

 

[monger]

I think the numbers have rebounded since the loses due to the 2013 flood. Fish were massive in 2015-16 with less competition around. The fish this year have greatly reduced condition factors (a lot thinner). I hope there isn't a problem with the invertebrate populations.

Hopefully the government plans to allocate more funds to monitor the population. Dr Post  at the U of C has a steady stream of students eager to crunch some numbers

[SilverDoctor]

Is anyone studying the invertebrate populations? We do trout counts but do we do trout food studies.

[fishteck]

The real problem with this subject is that most of the research, and citizen science has been limited in scope. There is a need to address the concerns of depleted fish populations on a Bow River Basin wide basis. The changes that have taken place in the trout population over the past 5 years do not appear to be consistent with normal events. Each of the five years we have seen dramatic changes. Larger fish one year, lack of a size class another and changes in conditions from highs to lows.

The Bow River has been neglected by our fishery managers for many years due mostly to the focus on the endangered and vulnerable fish management policies and  the presence of Whirling Disease. There is now a recognition that more resources need to be directed to the Bow River sports fishery. Before any change or improvement can be made to the fishery there is need for a baseline index to monitor shifts or improvements to the management of the resource. Fish population surveys would seem to be that index.

There are many different opinions as to why we have seen the declines in trout population over the past 15 - 20 years. River flow management policy, closures, water quality, habitat, fish feed and regulatory enforcement are just a few of the many possibilities. What is important at this point in time is for the fishing community and stakeholder groups to consider what can be done to improve the fishery. Hopefully the provincial government will engage the fishing community in the decision making process. If not others will do so.

[bcubed]

1 hour ago, fishteck said:

Before any change or improvement can be made to the fishery there is need for a baseline index to monitor shifts or improvements to the management of the resource. Fish population surveys would seem to be that index.

Would be nice to see an application of the precautionary principle a bit here, while we are catching up on data shortages. We also need to get a feeling of angler effort and potential impact..

[troutfriend]

let me help you with that....

"There are many different opinions as to why we have seen the declines in trout population over the past 15 - 20 years. River flow management policy, closures, water quality, habitat, fish feed, increased anglers, increased access and regulatory enforcement are just a few of the many possibilities."

[toolman]

Seriously, you think that the increase in C&R angling is the leading cause of trout population declines on the Bow over the past 15 years? It has some impact but studies have shown the effects are negligible.  

As for enforcement on the Bow, it has increased significantly since 2006. F&W told me back then that they only received 4 calls to RAP to report illegal fishing activities on the Bow, for all of 2005. 

Evidence based science is the foundation on which good management strategies are created.

The Bow isn't the only river that has experienced a 50℅ loss of Rainbow population over this time period. Several other major trout rivers in the US mid west have experienced the same decline. 

I feel that many of the issues that have had a very negative impact on the Bow fishery have long been identified. Doing more fish counts may not lead to any new information.

The problem is the political will to make the necessary changes. Lobbying efforts have fallen short thus far. When flows get dangerously low, the City of Calgary won't even place a  water advisory or enact water restrictions. Instead AEP closes the river to fishing. For the past five years the City of Calgary pays Trans Alta to draw down the reservoir levels 20,' at the Ghost Reservoir, as a flood mitigation strategy. This increase in flow can extend natural run off period by up to a month. The increasd flow  and subsequent turbidity, reduces sunlight penetration to the stream bed where the basis of the food chain starts. Aquatic mosses, plants, invertebrates and all marine life is negatively affected. This is followed by water hoarding in August to fill the reservoir back up to generate power. I could go on and on... Lorne Fitch has been sounding the alarm about many of these types of issues for a long time

        

 

 

[Dangus]

1 hour ago, toolman said:

Seriously, you think that the increase in C&R angling is the leading cause of trout population declines on the Bow over the past 15 years? It has some impact but studies have shown the effects are negligible.  

As for enforcement on the Bow, it has increased significantly since 2006. F&W told me back then that they only received 4 calls to RAP to report illegal fishing activities on the Bow, for all of 2005. 

Evidence based science is the foundation on which good management strategies are created.

The Bow isn't the only river that has experienced a 50℅ loss of Rainbow population over this time period. Several other major trout rivers in the US mid west have experienced the same decline. 

I feel that many of the issues that have had a very negative impact on the Bow fishery have long been identified. Doing more fish counts may not lead to any new information.

The problem is the political will to make the necessary changes. Lobbying efforts have fallen short thus far. When flows get dangerously low, the City of Calgary won't even place a  water advisory or enact water restrictions. Instead AEP closes the river to fishing. For the past four years the City of Calgary pays Trans Alta to draw down the reservoir levels 20,' at the Ghost Reservoir, as a flood mitigation strategy. This increase in flow extends natural run off period by about a month. The increasd flow  and subsequent turbidity, negatively  affects sunlight penetration to the stream bed where the basis of the food chain starts. Aquatic mosses, plants, invertebrates and all marine life is negatively affect. This is followed by water hoarding in August to fill the reservoir back up to generate power.

        

 

 

Your lawn ain’t healthy until it’s growing mushrooms in August!

[toolman]

Hahaha. Well said.

[Dangus]

Ya it blows my mind that they don’t put water restrictions in place.  Water meters=city gettin  paaaaaaid

[bcubed]

The problem will be similar to the NCNT. Fisheries management has a very limited set of levers to pull, mostly just reg changes. 

 

C&R May be relatively low impact when looked at in a silo, but cumulatively a 1-2% mortality starts to add up when you add in the other issues mentioned..

[toolman]

7 hours ago, bcubed said:

   

 

C&R May be relatively low impact when looked at in a silo, but cumulatively a 1-2% mortality starts to add up when you add in the other issues mentioned..

Actually, numerous studies on the long term impact of C&R on trout populations show that it has no significant cumulative effect. Nor does fishing over redds. 

If you take a look at the Bow regulations from the 80's and 90's, anglers were using bait, keeping trout, yet the population continued to flourish and expand during that period.

     

[Dangus]

32 minutes ago, toolman said:

Actually, numerous studies on the long term impact of C&R on trout populations show that it has no significant cumulative effect. Nor does fishing over redds. 

If look at the Bow regulations from the 80's and 90's, anglers were using bait, keeping trout, yet the population continued to flourish and expandd during that period.

     

Wasn’t there just a paper out that showed increased egg resorption in steelhead following the stress of catch and release?

[bcubed]

2 hours ago, toolman said:

Actually, numerous studies on the long term impact of C&R on trout populations show that it has no significant cumulative effect. Nor does fishing over redds. 

If look at the Bow regulations from the 80's and 90's, anglers were using bait, keeping trout, yet the population continued to flourish and expand during that period.

     

I’d be curious to see the report that speaks to the cumulative impact of whirling disease, water temp, a year class changing flood,  transalta’s ‘fun’, the substrate and turbidity changes as you d mentioned, as well as the pressure the Bow has. I know I sound like the good ol OHVers, but show me the money (science). Don’t forget that the 2005 assessment of the fishing at the highwood confluence was utilized at the 2014 PAC and described as ‘the rainbow trout populations are doing fine, so no reg changes needed’... turns out not so fine..

 

really, the decrease and timing sure points towards whirling disease to me...

 

regardless, hope this motivates the government to look at the Bow a little closer. We all took it for granted for a long time and I think we’re paying for it. Don’t forget the articles and videos from prominent guides about how the Bow was better then every following the flood, and no decrease in numbers...again, I hope that the fishery guys can motivate the higher ups to look a lot larger picture, as the only lever they can pull is reg changes. If anglers aren’t the problem, then how do we get to the larger issues (flows being my favourite topic)

[fishteck]

There is a great discussion here and probably the importance of knowing that the Bow River sports fishery may be in decline. For a long time government departments and NGOs have touted the Bow River as a world class fishery that is just there for everyone's taking. 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. Water management practices have given us the Bow River trout fishery but the 2013 flood tipped the balance to an extreme flood mitigation practice that could well have far reaching implications on the fishery and the hydrology of the river downstream of Calgary. The following is a proposed list of topics that need to be considered if any improvement in the fish population are to be achieved.

•    An ever-increasing number of anglers

•       Limited regulation enforcement.

•       Little to no commitment to river access additions and improvements.

•       Where do trout spawn – has this changed over the past 20 years.

•       Unknown fish population and reproduction dynamics

•       Fish population survey locations do not represent the Bow River stretch from Calgary to Carsland.

•       Improvement in water quality and the impact on trout feed supply.

•       Enhancement of fish habitat

•       Impact of climate change

•       Bow River Water Supply Management Plan – flood and drought control models. Up stream dams.

•       AEP commitment to management of a recreational sports fishery.

•       Logging influence on the fishery – Highwood River Basin and others.

•       Changing hydrology of the river – floods, flood mitigation practices.

•       Seasonal closures – short-term pain for long term gain.

•       Fishing regulation change – triple hooks, special status regs 

•       Management of all water craft use.

Give us some feedback on your opinions. It is hoped that we will get the ear of the government in the near future

 

 

[bcubed]

Sorry Peter, but how does ‘Little to no commitment to river access additions and improvements’ Possibly affect fish populations in a positive way. 

 

Also, I know you’re choosing your words carefully, but why is it a ‘may’ from your perspective. It seems pretty cut and dry, no?

[fishteck]

Brent:

The argument for and against new boat ramps has been debated for some time. The current belief by many jurisdictions across  North America and the basis for the new site proposals with the Calgary River Access Strategy was that "designated" access will restrict boat access to the river in such a way that it will not impact on riparian and fish habitat. The same argument applied to Policeman's Flats - indiscriminate river access to the river has more or less been eliminated with a hope that vehicle access to the entire property will not continue. In other words - containment of vehicle traffic. 

The argument that more boat ramps will give more people access to the fishery and thus increase fishing pressure has also been debated. More designated public boat ramps across the entire length of the Bow River should spread out the fishing pressure on those section of the river that have access. This surely would improve fish survival. If government agencies restrict development of new river access points you can assure yourself that casual river access across river banks and sensitive habitat will continue. Graves Bridge gravel bar is a good example. Once the free access to the gravel bar was eliminated by placement of a Lego blocks barricade, natural vegetation has taken over.

"May" is a politically correct word that seems to be appropriate at this stage in the discussion!  

 

[thedoubtingtrout]

Quote

On 15/06/2018 at 10:09 AM, fishteck said:

The argument that more boat ramps will give more people access to the fishery and thus increase fishing pressure has also been debated. More designated public boat ramps across the entire length of the Bow River should spread out the fishing pressure on those section of the river that have access. This surely would improve fish survival.

Is this true? As in, is there actually peer-reviewed science that supports this statement?  I'd love to see the evidence behind this statement...

On its face, this statement certainly makes no sense--why would increasing access "spread out" the fishing effort and "surely improve fish survival" when most of the fishing occurs in a pretty standard stretch of the river, anyway?  

-The Doubting Trout  

 

[FishnChips]

Quote

More designated public boat ramps across the entire length of the Bow River should spread out the fishing pressure on those section of the river that have access. This surely would improve fish survival.

This is specious logic. 

[Aiptasia]

3 hours ago, FishnChips said:

This is specious logic. 

What a fantastic term. Thank you for this, as I have never come across it. 

 

[monger]

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

[FinnDawg]

Did one get a hold of your finger too?

They have definitely moved up into the city section in the past couple weeks!

[fishteck]

Boat Ramp Access - impact on fish survival. The float from Graves Bridge to Policeman's Flats together with the float from Policeman's Flats to McKinnon's sees the biggest pressure on the fishery. Not only from the float angler but also walk in bank anglers. If you want to catch a scared up trout from multiple catch and release antics this is the place to go. Every time a fish is caught the survival rate has been reported to decrease. Hopefully more river access sites will spread out the fishing , reducing the pressure and mortality of fish population.

If one wants a more pristine experience and catch less scarface fish. go further downstream. Those fish you do catch will not have experienced the stress and damage for repeated exposure to  hooks, hands, nets and air. Historically bigger fish were always caught on the Mac to Carseland stretch of the Bow. Were they bigger because of more feed, or that they survived less catch-and-release?

Remember the boat angler may catch more fish, but represents such an insignificant pressure on the fishery as compared to the vast number walk in anglers. The pressure on the fishery comes from many directions, but the ever increasing number of anglers may be of the greatest concern. Spread them out on the river would give the fish population a better chance to survive. 

No science here! just and oldtimers logic. If we wait for the science community to take up our concerns and the fishery managers to take action to correct the situation based on scientific evidence there will be little or no fishery left!

[Dangus]

Personally, I would like to see more sewage effluent enter below bearspaw to improve that section. 

[BurningChrome]

 

2 hours ago, Bron said:

Personally, I would like to see more sewage effluent enter below bearspaw to improve that section. 

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...