You are what you eat Salmon edition

[Snidley]

Just read this from California.

California's endangered salmon population plummets amid new threat (yahoo.com)

 

Anchovies like Alewives are the culprit.  I wonder if this is the main cause of falling Chinny numbers in Ontario. 

[Fisherman]

Salmon introduced into the great lakes are just that, another non native specie that probably wasn't supposed to be there in the first place.  Then those fish farms are another disaster, shouldn't be allowed.

[Snidley]

I sort of work from the position that Salmon are desirable even as a nonnative fish. The alternative is to fish for lakers, from a boat at significant cost. My bet is that most anglers would not be keen on that scenario. The article really outlines the issue of naturally occurring chemicals in prey fish that negatively affect salmon at a molecular level. I believe that the same issue  condemned the Atlantic Salmon program to failure before it had any chance to succeed. I always thought the issue was exclusive to Atlantics and that Pacific salmon and Steelhead could ingest the chemical, which is found in Alewives. without it affecting their ability to spawn successfully. This study claims otherwise

[Fisherman]

I think the problem with Atlantics are lack of rivers/streams where they normally spawned due to dams and human building.

[Snidley]

You are probably right. They never got to the stage where a percentage of the total that would be lost to mortality over time, mattered. There was no "stage" it just didn't work so the demise is tracked along a short timeline, with high sunk investment going the other way like a rocket If grantee's did stream rehab then that would be good for other fish like steelies and smallmouth. I'm betting they did not due rehab work but sunk a lot into administration. AND monopolizing space on an entire hatchery for a while.

[Canuck]

Smelt also contain high levels of the thiamase enzyme.  Alewife also have a lot of thiamase enzyme in them.  But the salmon thrived when there were lots of Alewife in the lakes (that was why chinooks and coho were stocked originally).  Maybe not as good as they could have if that enzyme was not there, but they seemed to do OK.  Now that alewife are basically gone in Georgian Bay, the salmon are eating smelt as their primary food.  I think lake herring are probably depleted because of salmon predation too.  They may be the one food that the salmon truly thrive on and it is one of their main food sources in the oceans.  Anyway, likely multiple reasons for declines and I expect that warming waters is part of the whole picture, and impacts both salmon spawning and probably the food bait spawning and down the food chain.  

Edited January 5, 2023 by Canuck

[Snidley]

It seems like the story of thiamase is complicated. If it inhibits salmon spawning it should have destroyed the fishery by now. Even with stocking the DNR's in Ontario and the US are using either brood stock or eggs harvested by milking staging fish. If the eggs were not viable there should be little to no success in stocking the beasts. Buy if you stock there will be salmon. At some point it might be worth DNR's looking to genetically modify salmon genes to make Thiamase a non factor in reproductive success. There might even be a place for stocking lake Herring so as to replace the current forage base with one that eliminates the problem at source and also provides an original forage base that is also a game fish that's fun to catch in it's own right. All of this would take money and we know that will be in short supply in the coming years so it probably won't happen. I can say that salmon fishing was much better this year than last year at least for me. 

[John Bacon]

On 1/5/2023 at 12:55 PM, Snidley said:

It seems like the story of thiamase is complicated. If it inhibits salmon spawning it should have destroyed the fishery by now. Even with stocking the DNR's in Ontario and the US are using either brood stock or eggs harvested by milking staging fish. If the eggs were not viable there should be little to no success in stocking the beasts. Buy if you stock there will be salmon. At some point it might be worth DNR's looking to genetically modify salmon genes to make Thiamase a non factor in reproductive success. There might even be a place for stocking lake Herring so as to replace the current forage base with one that eliminates the problem at source and also provides an original forage base that is also a game fish that's fun to catch in it's own right. All of this would take money and we know that will be in short supply in the coming years so it probably won't happen. I can say that salmon fishing was much better this year than last year at least for me. 

At Ringwood, we treat the salmon with vitamin B baths to combat the effect of thiamase.

I have heard figures of 10% mortality from EMS (early mortaliy syndrome) relating to thiamase.  10% isn't going to destroy a fishery on it's own.  But an additional 10% on top of other challenges such as less than ideal river and creek habitat may prevent a species from establishing a self sustaining population.

  

[fishdawg]

On 1/3/2023 at 1:38 PM, Fisherman said:

Salmon introduced into the great lakes are just that, another non native specie that probably wasn't supposed to be there in the first place.  

Maybe but they (plus rainbows & browns)  have been an incredible success story!

[Fisherman]

Success of what, money to sell equipment, boats, and a pile of other stuff.  It's pretty much a put and take effort.

[Snidley]

I would say that the financial success of equipment and boat sales is indicative of the enjoyment we have catching them. If the MNR had their way we would have the Great Lakes crawling with lakers and almost no one would be fishing for them. To me, this is what I expect from a fisheries ministry a fishery that I want to participate in.

[captpierre]

On 1/6/2023 at 8:23 PM, Fisherman said:

Success of what, money to sell equipment, boats, and a pile of other stuff.  It's pretty much a put and take effort.

I thought natural reproduction was significant with Kings and Cohos on the Canadian side. Poor on the American side. That’s why they are stocking  more. 

[Fisherman]

Maybe they're better fishermen and need more, lol.

[CrowMan]

 

"I thought natural reproduction was significant with Kings and Cohos on the Canadian side. Poor on the American side. That’s why they are stocking more"

True. A lot of the tributaries on our side of Lake O allow better access to cold and clean nursery waters.

However, the fact that the annual budget for the OMNRF is $640 million CDN, and the budget for NYSDEC is $1.8 billion USD just might have something to do with it...

For context...Ontario has a population of 14.5 million, NY State has 18.3 million...not a big gap, but they spend almost 4 times more than us on fish & wildlife...and, of course, our land mass is 8 times larger..

And NY State sales tax is only 4%...

Edited January 19, 2023 by CrowMan