Bow River Brown Trout Redd Survey

[jpinkster]

In November 2015, the Bow River Chapter (BRC) of Trout Unlimited Canada conducted its first annual Brown Trout Redd Survey of the Bow River. The project was initiated to acquire baseline and trend through time data, as well as to supplement data from similar surveys completed on the Elbow and Bow Rivers by other organizations including Calgary River Valleys.

 

On November 7th and 8th of 2015 a group of three Crew Leads and up to five volunteers per crew surveyed 21.2 km of the Bow River, between Graves Bridge on Glenmore Trail to Policeman’s Flats. Survey methods included physical observations for redds either from three rafts, floating along river left, mid and right in tandem, or by foot with travel limited to on top of the banks.

You can see the full report on our website: http://bowriver.org/2016/11/01/2015-bow-river-brown-trout-redd-report/

 

 

Having this baseline data is important. With better information we can make better observations on brown trout spawning trends in the Bow River. Our team will be out again in a few weeks to carry out the 2016 Brown Trout Redd Survey. Please visit our website if you are interested in participating: http://bowriver.org/2016/10/29/bow-river-brown-trout-redd-survey-november-13-2016/

[BurningChrome]

Really happy to see this report and very nice presentation of the data. Glad to have been a part of this and looking forward to doing it again this year so we can get some comparative data.

[fishteck]

An excellent project with very encouraging results. There is very sketchy data available on brown and rainbow trout spawning activity downstream of Policeman's Flats. There are many back channels all the way down to Carsland. It would be nice to see what spawning takes place. Keep up the good work BRC!

[Dangus]

Can't help but notice the outdated image of the river.

Serves its purpose, I guess. Results/hot spots are consistent with what I've seen so far this year on floats.

[bcubed]

Can't help but notice the outdated image of the river.Serves its purpose, I guess. .

ESRI aerial data isn't updated as often as google maps so it is what it is when having a GIS project completed for free...

[BurningChrome]

Can't help but notice the outdated image of the river.

Serves its purpose, I guess. Results/hot spots are consistent with what I've seen so far this year on floats.

If you have free access to more current imagery TU can always use more volunteers to help with these things.

[Dangus]

Do you have to pay google to use it for those purposes?

[BurningChrome]

Do you have to pay google to use it for those purposes?

Google maps imagery is free to use for non-commercial projects. The issue is the GIS software used to map the redds on the imagery doesn't have access to Google maps imagery for free (if at all). The most current and up to date map imagery is not vital to this project though - even the geolocation used for redd location was not the most accurate. Come out for the 2016 survey and you can get a better idea of how the sausage is made.

[Dangus]

Wasn't trying to knock the work BC. Just noted the old map and how it affected how spawning areas were recorded.

Sending you a pm

[FlyTrapper]

Any minimum age requirement on volunteering?

[bcubed]

Any minimum age requirement on volunteering?

 

I'll find out for you.

[fishteck]

Calgary River Valleys has been coordinating redd counts on the Elbow River for 20+ years. The 2015 survey showed an encouraging increase in redds over previous years.

 

http://calgaryrivervalleys.org/2015-redd-count-a-brown-trout-resurgence/

 

These data conbined with TUC - Bow River Chapter survey results speaks well for a sustainable Bow River brown trout population

[BurningChrome]

These data conbined with TUC - Bow River Chapter survey results speaks well for a sustainable Bow River brown trout population

I think it might be premature to say anything since we don't have any comparative data for the Bow yet. There's no way to say that an increase in redds in the Elbow didn't coincide with a decline on the Bow because we're missing data prior to 2015. It's good to see that there was an increase from 2014 to 2015 on the Elbow, but it's also interesting that there was a decrease from 2013 - count would've been after the floods - to 2014. Is there an associated report to go with their data that offers insight?

 

I'm looking forward to comparing the 2015 and 2016 Bow river counts, but until there are at least a few years of data for it I don't think we can claim any trends.

[Conor]

Bing has free source geolocated imagery if you wanted to use that. Usually within a year or two current.

 

If time commitments are flexible, I could likely provide some GIS support. Just reach out if interested.

 

Any talk of using drones for these surveys? They are an economical way to cover areas, give flexibility for timing of data review, and are safer overall. Some jurisdictions in the states have developed solid protocols for using them for red surveys.

[jpinkster]

Bing has free source geolocated imagery if you wanted to use that. Usually within a year or two current.

 

If time commitments are flexible, I could likely provide some GIS support. Just reach out if interested.

 

Any talk of using drones for these surveys? They are an economical way to cover areas, give flexibility for timing of data review, and are safer overall. Some jurisdictions in the states have developed solid protocols for using them for red surveys.

 

We have had a few conversations about using drones. It is important that we recognize that while this study gives some great information...but it is not exact science. Drones would likely give us a more accurate redd count.

 

A big part of this is really about getting people active in conservation efforts on our river. This redd survey is a lot of fun and it is fantastic to see regular folks getting involved. I would worry that if we did drones and not rafts, we may not see the same "team building" level of participation.

[bcubed]

I think drones could be appropriate downstream of the city, but within the city would not be worth the headache or liability.. way too many people, go through a provincial park, near highways, people... If there are a couple folks with drones out there that are willing to donate time, im sure BRC could line up something downstream of Police.

 

I'd question them being more accurate, but just a different way of doing them, and less people-intensive. Considering the number of redds that were associated with overhead cover, undercuts, and in varying water clarity.

[jasonvilly]

There was just an episode on Discovery's Daily Planet about the use of drones and biological surveys.

 

They were testing drones that had algorithm software to count birds on a beach. They also had humans count the same fake birds from a distance.

 

The humans were far more accurate than the drones, there were some problems with the identification algorithms (picking up people as birds etc)

[jpinkster]

Especially with shooting over water, there could be some issues with picture quality. Without the proper lens, you'd have a lot of shots that would be totally washed out from the glare.

[troutfriend]

Note; if you change the methods of the study design (ie people to drones) then it fundamentally changes the experiment - if you are looking for trends and looking to compare between years... . Drones are amazing tools, but would not likely be able to see the redd depression.

 

Redd surveys are great in that they engage public, get people working together and help individuals better understand the science, observing what type of habitat fish require and use, get people talking about other local issues and enjoying being together in the field, but they cannot really be used as a accurate representation of what is actually happening at the population level as number of redds observed does not directly relate to numbers of fish hatched out.

 

For those that have not had the opportunity to participate, it is well worth the time to go search for redds.

[jpinkster]

^ smart guy up here

 

 

Redds say more about habitat than they do fish population. High concentrations of redds is a great thing because it speaks to quality spawning habitat. Of course there is a correlation between the two, but it isn't a seamless indicator.

[BurningChrome]

but they cannot really be used as a accurate representation of what is actually happening at the population level as number of redds observed does not directly relate to numbers of fish hatched out.

Absolutely correct and not all fish spawn every year either. I think it can show things like streambed health in areas - if there were lots of redds in a certain area one year but none the next, did something change at that spot like lower flows made it unusable? Drastic changes from a baseline number of redds would also likely indicate something was up. Either way, numbers and locations don't tell a full story which is why you'd need to do some additional research.

[ginger]

Thanks to Trout Unlimited/BRC for this study. Also the number of redds in the Mallard Point side channel speaks to the efficacy of their Mallard Point project. I think many of us noticed that big Browns were back this year. So support TU/BRC and ATTEND THE FALL SPLASH coming up Nov. 24

[jasonvilly]

What defines quality spawning habitat?

[bcubed]

What defines quality spawning habitat?

 

Flow velocity, depths, substrate, overhead cover, groundwater inflows, etc

 

sign up and we'll show ya!

[fishteck]

Lots of talk about "research" & "science" on this post. It is important to understand that biological based field studies and surveys by their nature are just a record of events at a point in time. The variables from year to year are beyond the control of the investigators. The best result one can expect to see is a trend over the course of a number of observations. In this case years. The greater the number of observation (years) the more reliable the data will become.

 

Even if an increase in redds is seen from year to year, it may not necessarily correspond to and increase in trout populations. Habitat improvements, reduced river flows, changes in climate may all have an impact spawning success, both positive and negative! In addition, the increased pressure on the fishery and a corresponding increase in mortality, especially on large brown trout within the city could well negate any benefits derived from increase spawning activity. Closure of the Bow River city reach to fishing in October and November would give the greatest protection of our brown trout population. Will this ever happen? Very unlikely.

 

But as I have stated previously, the surprisingly high numbers of redds observed in the 2015 surveys, especially the Bow River would support my statement that the Bow River has a sustainable population of healthy Brown Trout.