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[Rodney]

Tomorrow evening I will be showing a presentation made by Steve Johnston from UBC's Pacific Salmon Ecology and Conservation Lab back in early February. It's about his ongoing study on post-release mortality of chinook salmon in saltwater around BC. The presentation is about 45 minutes long, with plenty of interesting background info and fascinating findings. The video starts at 7:30pm and Steve will be joining in the live chat to answer your questions while the presentation is shown.

https://www.youtube.com/watch?v=8nThmHxQkaE

[Dave]

A very timely subject right now among salt water salmon anglers. Thanks for putting these educational seminars out there Rod.

[alindsey]

Do you touch on freshwater C&R or only saltwater?

[Rodney]

Do you touch on freshwater C&R or only saltwater?

This particular study is on saltwater only.

[Rodney]

Bump. Video to begin shortly.

[wildmanyeah]

Thanks for putting it on Rod, I watched it live and had some of my questions answered.

There is definitely some stuff i can see on the horizon with this type of work.

[CohoJake]

FYI, there is a study underway in Washington waters on using only large plugs to catch winter chinook - with the hope that it will reduce the undesired catch (and necessary release) of undersized chinook, thereby decreasing the total impact on protected chinook populations.  Initial results sound promising.  I don't have a link, it was just mentioned at the WDFW season forecast meeting on Feb 28. I don't believe they are studying the release mortality using these plugs, but the idea is to avoid hooking the fish that need to be released in the first place.

[DanL]

very interesting presentation and methodology. a lot of info to unpack

Interesting that total mortality was about 20%, though as the presenter noted, it's hard to put into full context since there isn't a proper control group. Given that natural mortality presumably can't be zero, maybe the fishery induced mortality isn't that bad. If C&R killed 20% of releases, one would think that'd be untenable...

The part about eye injuries was kind of disconcerting. Dont know much about it, didnt realize that many fish can be hooked through or around the eye. Something like 50% hookups resulted in eye injury when using the largest hooks in the study? That's horrifying, and (maybe unsurprisingly) was the highest correlating factor to increased mortality.

For the salt guys, are eye-hooks really that common? Based just on my local flow experience, eye shots basically never happen because the hooks we use are generally too small for that to be possible.

[ribolovac02]

From all my saltwater Experience , mostly guided , wcvi , Eye injuries Are acurring regularly , but the places i went to, dont practice or Encourage catch and release, it’s all about get your limit and get out .
I always questioned why they use such large hooks tho .

[RalphH]

Most surprising to me was the survival data. Assuming I understood this correctly, the sample data had survival rates of 75 to 80%+ of those fish that had been landed. That's is survival of mortality from all possible sources. If it's at that rate how serious is the threat from seals, orcas etc? They also seemed to find some evidence of multiple angling captures. That's usually associated with intense inland fisheries and may indicate just how intense our Salish Sea salmon fishery has become.

[wildmanyeah]

Most surprising to me was the survival data. Assuming I understood this correctly, the sample data had survival rates of 75 to 80%+ of those fish that had been landed. That's is survival of mortality from all possible sources. If it's at that rate how serious is the threat from seals, orcas etc? They also seemed to find some evidence of multiple angling captures. That's usually associated with intense inland fisheries and may indicate just how intense our Salish Sea salmon fishery has become.

The High survival rate IMO had to do with the relatively close distance most of the captures were to their native spawning rivers.  I am not surprised there is not a high orca related mortality as the study kinda took place right in between the Northern and Southern resident territories. The SRKW pretty much never go that north into the SOG and the NRKW don't spend a lot of time that south in ECVI. The seal thing to im not surprised as most of the fish were hatchery fish all returning in pretty high numbers. I think most of the studies say seals are more of an issue for the out migration than the return.

Doing this same study in Haida Gwaii im May and June would probably have vastly different results.

If anything i think this study helps make the case for terminal fisheries.

[RalphH]

fair points though most of those fish were moving well south, some as far  south as Puget Sound and even the Columbia. I also noted that the animation to show the movement of tagged fish showed most of them moving down the centre of the Gulf with some stops at specific locations - such as Cape Lazlo - perhaps for foraging.

[wildmanyeah]

I believe the animations between two receivers are purely for animation purposes.  As far as i know where fish go between receivers is largely unknown.  I think they just pretty much animate a straight line between receivers.  at least thats what ive seen in other Kintama Telemetry Studies.

http://kintama.com/visualizations/

http://kintama.com/animator/dep/Hinch2020/  Chinook

http://kintama.com/animator/dep/Chilko2017_sockeye/

http://kintama.com/visualizations/bc-salmon-conservation-studies/bc-steelhead-migrations/

From A C@R study in the JDF

2019 http://kintama.com/animator/dep/AdultChinook2019/

[RalphH]

Ok it must however they can pretty much guess the path they have taken based on elapsed time. It was mentioned in the video migration speeds south was 20km+ per day.

[Rodney]

If you go to the video link again, Steve has answered some of the questions in there. I'll try to get him to log into here to provide more information if interested.

There will also be another video on coho salmon post-release mortality, but this isn't coming until much later this year or early next year. Expect to see more academic related video content.