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I feel that the study is somewhat myopic. However, I also feel that the old data was wildly optimistic. 4,200 Trout per Mile ?? Bullshit.. It used to be advertised on Country Pleasures Brochures, Pre Dating Internet.. Wonder where that Data came from.. I feel that our Bow is going Downhill, FAST.. I believe Whirling Disease has been here for over a Decade. I believe that Trans Alta is Hugely responsible.. Spin the Dams Up For Profit,, I have never scene the Bow at 52 CMS IN September until this year.To Hell with any environmental Considerations. I feel That Fishing pressure is A Main Factor.. I have never witnessed the pressure of 2018.. As far as The Guiding question...Might be a good time to cap the number of Rod/Boat Days and totally Shut Off BC and Montana Guides.. I have Fished the Bow in the 60s.70s.80s,90s.2000s and the 2010s.. I know that Single Hook, Barbless and Seasonal Closures would Help, Immensely.. Very Complicated Issue and no EASY Answers...

I believe many are looking at the Cahill's publication for more that what it is - a retrospective statistical analysis of field study data over a 10 year period. There is little accountability of the variables from year to year in any of the population studies. Statistical modelling can account for some of the variables - but not all. Regardless, the publication does support what many have been saying for years, that the trout population is in decline and action needs to take place to stop the decline. Have a look at the following link that will take you to a summary of all the reported fish population studies prior to the 2013 flood. The trout population and proportion of rainbow and brown trout varied from survey to survey and in general the reasons for the variations were purely speculative. Nevertheless Cahill's publication has moved focus by AEP away from exclusively endangered native species of trout to some management of the Bow River sports fishery. I believe many of us would believe that this is a good thing. https://bowrivertrout.org/2018/06/13/the-state-of-the-bow-river-fishery-trout-populations-may-be-in-decline/

The creel survey last year wasn't an accident..

I would need to see the "three different quantitative models " to decide on the seriousness of the problem. My first thought is perhaps the spawning grounds in the Highwood River might be under pressure. Have the rainbow spawning grounds been looked at in this study? There are a lot of factors involved and how do weight each stressors in your quantitative model? The thing that worries me is they say don't know from their model/data what caused the population decline but are quick to suggest an easy "fix" of limiting fishing? Perhaps there are more serious factors in decline that need addressing as well.

This article has generated considerable debate on this board, our Bow River Trout Facebook page and others that have similar interests in a sustainable trout population for the Bow River. It is important to recognize that the historical Bow River fish population surveys were conducted on one of the most productive stretches of the river between Policeman's Flats and the Highwood River. And at that time were considered to be representative of the lower Bow River trout population. The 2005 and 2013 floods change that - the stretch of the Bow River below the Highwood was hit far harder than above by the two flood years and there is general belief that the fishery has never fully recovered in that area. The more recent fish surveys did include data collected from below the Highwood River and above Policeman's Flats therefore it is not surprising to see a decline in trout populations. What the data does indicate is that the trout populations across the entire "Blue Ribbon Bow River" from Calgary to Carsland dropped by as much as 50% for Rainbow Trout from 2003 to 2013. The end result has been that AEP started a new series of fish population surveys across the entire Bow River sports fishery from Bearspaw to Carseland in 2018 to establish a baseline to develop future fishery management protocols for the Bow River. This is a significant step in the management of the Bow River sports fishery. On the subject of variable Bow River flows - It is very easy to point your finger at TransAlta, but the Government of Alberta sets the protocol for Bow River water management. In July 2018 the daily variable flow were extreme. When we expressed our concerns for the fishery and potential impact on the fish survival itself immediate changes to the daily water management protocol were made and flows stabilized as best that TransAlta could do for the remainder of the year. The recently installed flood mitigation protocol for the Bow River may be our biggest challenge. The recommendations presented to the GOA were flawed in so far as not addressing the impact of modified upstream dam operation on the downstream ecosystem - specifically the sports fishery and associated environment. Bow River Trout Foundation has expressed our concerns to AEP Minister Phillips - we are awaiting a response. Needless to say, it will take time to make change to water management practices to enhance the sports fishery, but we continue to be hopeful. In closing, it may be worth following our website blog page for information on the Bow River fishery, we try to keep it up to date on current issues. http://www.bowrivertrout.org Bow River Trout Foundation

The study is based on historical F&W data collected in-house or via consultants. Over the years the sampling methods/areas/timing have been anything but standardized. In order to make sense of the available data, it was quite heavily massaged with some pretty complex statistical math. There are a large number of factors that can influence the river's productivity and population counts. A couple of major floods had very serious consequences in the short term, but the system seems to be able to rebound over time. There have been times when there was less fish around and times when the fishes' condition factors have been below what we normally expect. At present, things seem to be on the poor end of the scale (especially the rainbows). One thing about this study that I see as a blinking light.....there needs to be a standardized system established for collecting data so that we can compare numbers over years without creating fudge factors. Experimental design is a very valuable exercise before you even leave the desk to grab your electroshocker. So many complex things to consider, very few of which we may even be able to control. One thing that is easier to measure is the number of anglers and angler effort. The angler population has really exploded over time, and the average skill level is probably increasing as well. This angler effort is one thing the government can attempt to control. If angler effort is something they want to control, then the government needs to pay special attention to a subset in the angler population that is having the most impact in the fish handling arena....namely the guiding industry. Day after day pounding the water, skilled folks are putting a lot of pressure on this "threatened" resource. If the government wants to limit anglers and their impact, they better shine a bright light on the guiding industry before they start limiting access to Joe Public. Just a thought.

For those that want to read the report rather then the press release, BRT has it on their site: https://bowrivertrout.files.wordpress.com/2018/08/cahilletal-2018.pdf

I don't fish the Bow much, and thus there are others on this Forum who know it way better than I, but from following the threads here post-2013 flood, it seems to me that there has been much mention of relatively fat, healthy browns in the Bow, and more long, skinny rainbows. I read somewhere years ago that browns are more tolerant of higher water temperatures and pollutants/contaminants in the water than rainbows. Has there been any long-term tracking of these variables, alongside the flow rate monitoring? The article on the aforementioned study pretty quickly goes to angling pressure as a contributing factor. While no doubt this is a contributor, it would be nice to see acknowledgement of other changes in the river as well. For example, the monstrous Enmax Shepard combined cycle power plant came on line a few years ago, and uses treated wastewater from the Bonnybrook treatment plant as its cooling water supply (water that would otherwise be discharged into the river). And then there's my personal favorite, TransAlta's ongoing screwing with river flows to maximize upstream hydro profitability in Alberta's volatile power pool (wait until their PPA's expire in the 2020-2021 time frame, and then we'll REALLY see screwing around with the flows)...and on and on it goes. One more (perhaps) obscure one: I saw an article a while back that talked about the impact of forest fire smoke on emergent insects. Can't have been a good couple of past summers on that front...