The Northern California Fly Fishing Board

Wonder if it has anything to do with them dropping the river shortly after the spawn leaving tons of redds above water?

2007 Trinity River Hatchery Chinook Totals show the same trend with a huge lack of juvenile or jack salmon returning last fall.
T-Ball

The disturbing trend of the lack of juvenile/jack salmon has been observed on virtually every river in the west. On the A, while the adult return was only 1/3 of "normal", the juvenile return was 1/25 of "normal". This does not bode well for the future of salmon with a future population "crash" coming very soon. Expect more restrictions in both comercial and sport fisheries for salmon in the near future. Most scientists think that the current decline is caused by the lack of upwelling in Pacific waters, which in turn decreases the food supply. The cause of the lack of upwelling is not completely understood, but many scientists tie this in with global warming effects.

One would think that global warming would cause increased upwelling...

I'll defer any comments to Bob on this topic, but just as an intrigued casual observer of this I seem to recall that a noticeable drop in upwelling appears to be associated with el nino patterns. It is interesting to note the surface water temps when plotted across the equatorial Pacific (Australia to Ecuador-Peru) increase when the associated currents appear to reverse as the surface water temps increase, slam back into the South America and spread out both north and south along the landmass of the continents that prevents the currents from continuing in a east to west fashion. The end of the el nino usually has an affect on the upwelling off the Farralon Islands, which in turn brings about a smorgasbord for aquatic species as noted at the end of the last el nino by the local news reporting agencies. Without the upwelling of nutrient rich cold water, it seems that the food chain just collapses. Wouldn't migratory species also avoid dead zones in the ocean as they make their way to and fro? With the warmer water temps along the landmass, we also have sub tropical species enter the area as well. I can recall during one of the last el ninos when water temps were round 70 degrees off of Half Moon Bay compared to the average water temp runs around 54. During el nino years or sometime when there were low returns of salmon in the area where and when my father fished commercially, sometimes the salmon were void of any baitfish in their stomachs. I always thought this was odd, but never really paid much attention to it as a kid.

I am not associating the upwelling or lack there of to global warming, but the reported el nino effects. What I also found interesting was as a drought fear continued and the water management shifted away from other primary concerns, water temps below dams increased in the rivers as well. Last shad season, shad were hard pressed to enter rivers under discussion as well. The American River in particular had a low flow back in June 07 that was increased because smolts still in the river were affected by the higher than normal water temps. Al Smatski, whom we had fished with over a course of a couple of days, said the powers that be, either F&G biologists or others, had concerns because the scales of smolts were falling off. It struck me as odd at the time; from a curious stand point only, how this problem was being dealt with by numerous agencies as a water management issue to cooperate to drop the river's water temperature. Sure enough, over night flows from Folsom were increased after it was determined that there were sufficient acre-feet behind the dam to sustain the flows if increased. Not only did the water temps drop to safer levels, the shad moved upstream over night as well from their holding areas the day before.

Bob's point about the return levels on the A, it would be interesting know what the numbers/percentages were by the time they made it out of the Golden Gate area on their migration for the corresponding year.

It will be interesting to see how this plays out in the future.

It is interesting to note the surface water temps when plotted across the equatorial Pacific (Australia to Ecuador-Peru) increase when the associated currents appear to reverse as the surface water temps increase, slam back into the South America and spread out both north and south along the landmass of the continents that prevents the currents from continuing in a east to west fashion.

This should have read "west to east" instead of what was posted in order to make any sense.

Also, on Blanton's board a poster makes reference to an Oregon State University study of the delayed upwelling in 2005 causing ocean temps to increase due to changes in coastal ocean currents. This coincides with my remarks on equatorial current changes to reflect a reversal in surface water temps pushing from Australia moving eastward and along the coast of South America and pushing both north and south along the landmass and warming the waters as it moved in those directions. Deep water upwelling off the coast of California finally reversed this warming trend. If my recollection is right, this is when the nutrient rich bio mass off the coast was reported as well.

Since then, there was another obscure report of phytoplankton near the bottom of the food chain that had a massive collapse/die off for some reason. From the report, it mentioned that zooplankton was dependent on the phytoplankton that died off and would cause problems somewhere else immediately along the food chain (if someone is more familiar with this, please jump in and correct me). At the time it seemed like a wait see scenario as the other shoe dropped. The decline of salmon along Pacific coast might just be part of the equation being played out on larger scale that we are focusing on as a group. The explanation of the 2007 salmon fishing closures along the coast and the newer marine sanctuary closures were perhaps just the tip of the iceberg, so to speak.

At any rate, it has definitely keyed my curiosity.

I have included the July 2005 article from SFGate.com along with a similar article written the winter of the same year at following URLs

http://www...05/07/12/MNG8SDMMR01.DTL

http://www...ming-pacific-515074.html

Hey All,
That was my post on Blantons board.The O.S.U. study can be seen at...
http--www.compassonline.org-pdf_files-AAA...
I love fishing and fishing and this kind of thing scares the hell out of me.
RAS

Iknew I was going to screw this up.
Here's the complete information,
http--www.compassonline.org-pdf_files-AAAS2007PredictingPR.pdf
I hope this works,RAS

Concise synopsis of the state of the fishery on the Yuba from the South Yuba River Citizen's League (SYRCL). In the words of biologist Mark Kurd, "This is bleak. It is very, very, very disturbing".

Quick synopsis- http://syrcl.org/news/news.asp?id=176

http://www...assonline.org/pressroom/

Once you get there, click on any of the press releases. I think the pdf are then downloadable from there. Thanks for your post and link. That is an interesting site.