Fraser River is now so warm it may kill migrating sockeye salmon

You bring-up important points, WMY - thanks for that:

1/ Fish get stressed at higher water temperatures and their immune system is depressed, and
2/ For some viruses there is a correlation between elevated water temperatures and virus activation.
 
You bring-up important points, WMY - thanks for that:

1/ Fish get stressed at higher water temperatures and their immune system is depressed, and
2/ For some viruses there is a correlation between elevated water temperatures and virus activation.

There’s much more than viruses to worry about re salmon and warm water. Bacterial and parasitic infections are exacerbated during warm water events, warmer water has less dissolved oxygen, meaning swims through places like Hells Gate are for more draining on fish, and at 19° C, sockeye sexual maturation hormones can basically stop functioning, meaning eggs and sperm can be compromised to the point where the fish dies before gametes are viable.

There have always been 2 schools of thought from fishery managers when high water temperatures or high water discharge occurs when sockeye are migrating in the Fraser. One says leave the fish alone (ie no fisheries) to ensure as many spawners as possible make it, or the other side, who say harvest them because they will die anyway. I have always sided with the first group.
 
not arguing points above - but if you recall, the summer of 2014 was also very warm and the Fraser temps were warmer and yet the return this year seems reasonable/large (thus far) and everyone has tight pants in the front...
lets see what happens...

and yes, warmer temps overall aint no good at all!
 
not arguing points above - but if you recall, the summer of 2014 was also very warm and the Fraser temps were warmer and yet the return this year seems reasonable/large (thus far) and everyone has tight pants in the front...
lets see what happens...and yes, warmer temps overall aint no good at all!

In 2014 the water temperature on August 1 was above average at 18.4 degrees, that was 0.7 degrees above normal and still well below the 20 degree threshhold that is considered a problem. Yesterday the Fraser was at 20.7 degrees, 2.7 Degrees above normal. In 2014 the temperature did reach 20.1 Degrees on August 21 before dropping back down by August 27th. This year the Fraser has gotten warmer sooner than in 2014. It is forecast to drop back to 19.5 degrees next week though , and DFO is increasing escapement targets by 20% on early summer runs as a result of the high temps, so it seems they are going somewhere between harvesting them and leaving them alone.
 
https://www.psc.org/publications/fraser-panel-in-season-information/

Environmental Update
On August 16, the Fraser River water discharge at Hope was about 2 ,731cms, which is approximately 17%
lower than average for this date. The temperature of the Fraser River at Qualark on August 16 was 19.2oC,
which is 1.2oC above average for this date. DFO’s Environmental Watch program projects that river
temperature will increase to 19.5oC by August 22, while discharge is forecast to decrease to about 2,489cms over
the next 10 days. Sustained water temperatures in this range can cause severe stress to migrating sockeye and
may lead to significant en-route mortality. Prior to the season, the Fraser River Panel increased the lower river
escapement target for the Early Summer-run aggregate (which are the dominant group migrating up the Fraser
River at this time) by more than 20% to compensate for pre-season expectations of en route loss. If the current
pattern river temperatures continues, an increased fraction of the run may be required to compensate for
in-season expectations of en route loss. Migration conditions for Fraser sockeye will be monitored closely over the
next several weeks and if appropriate, additional management actions will be taken. To date fish condition
throughout the Fraser river has been good.
 
Wonder how many have been caught that have jaundice? Wasn't it prv +warm temps = hsmi? Which can lead to whiter fish or fish with jaundice. Wasn't something like that being sold here awhile ago?

With all the fish returning and the temps so high were are all sick diseased salmon?
 
Well.....I can tell you the last 2 days half the fish on the Fraser have been torn shreds by nets. Some have their gills half ripped out, flesh missing etc.
I am sure that this has nothing to do with pre-spawn mortality!
 
Hard to believe. I just spoke with a FN buddy. They are bidding on a contract to go seine 400,000 sockeye our of the kootenay lake. The fish struggle to make it that far and then they take them out when they are pretty much worthless. I’ll never understand DFO.
 
Hard to believe. I just spoke with a FN buddy. They are bidding on a contract to go seine 400,000 sockeye our of the kootenay lake. The fish struggle to make it that far and then they take them out when they are pretty much worthless. I’ll never understand DFO.

Sockeye would really struggle to get in Kootenay lake, since it has Kokanee not Sockeye. and they have suffered large declines, down to just 20,000 fish from historic numbers of up to 2 million, due to the introduction of mysid shrimp and the effects of the Duncan Dam.
 
Environmental Update
https://notices.dfo-mpo.gc.ca/fns-sap/index-eng.cfm?pg=view_notice&DOC_ID=212674&ID=all

The observed water temperature at Qualark on August 23 increased to 18.0
degrees Celsius which is 0.3 degrees Celsius above average for this date. Water
temperatures are forecast to decrease to 17.2 degrees Celsius by August 29,
2018. The Fraser River discharge at Hope on August 23 was 2,187 cubic meters
per second which is 24% below the average discharge for this date.
 
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