squamish chum retention = 0

marooned said:

How would the 03 flood have affected this years run ? I'm just curious, not trying to be confrontational Just trying to understand what's going on.

Click to expand...

Picture this!

In September 2003,the squamish is alive with coho's and chum near mid month to late september.Early october rolls around the place is plugged with spawning chum and coho's. The the rains come and there is aa flash flood that hasn't been seen for fifty years.The rivers are overflowing to th epoint of evacuating people from their homes.The river is over flowing with extreme violence.This is what would wiped any exhisting spawning beds and killed quite a few salmon.The river drastically changes everywhere and where there used to be river is now dry land.No salmon eggs survive on dry land.

Now at this point the river is very unstable in it's new path and there are still a good number of fish in the system who continue to spawn.Now the river rises at every small rainfall and wipes out more exhisting spawning beds.In the year 2003 several high waters were detromental to spawning salmon in the Squamish river system.

So inturn the returning number of salmon four years later in the year 2007 is extremly low due to in river mortality because of the floods.As well the low numbers of fish that survived the floods would have had a tough go out in the chuck.

Hope tis helps!



Hotrod

--------------------------------------------------------------------------------I TOOK THIS FROM ANOTHER SITE THOUGHT IT WAS INTERESTING

It does seem like gloom and doom with the coho returns so weak last year followed by few sockeye this year and perhaps weak
early (3 year old) chum runs as well. The most likely reason is that there was a body of warm water on the west coast in 2004 and into 2005 that reduced the winds that create the upwellings that cause the diatom algae blooms that in turn feed the krill that virtually all salmonids depend on. The collapse of the krill results in poor survival of salmonids, especially as they first leave fresh water for salt water. The dependence of young salmonids (as well as cod, pollock, hake, dogfish sablefish and herring) survival on krill has been thoroughly studied by DFO biologist Ron Tanasichuk out of the Bamfield Marine Sciences Center.
Tanasichuk is amazed by how much the biomass of krill can vary from year to year. "Over the last 15 years, the annual average biomass of sub-adults has varied by 10 times and the biomass of adults by 100 times."
"Over the years, opinions have changed from thinking that it's the freshwater phase that determines returns to the current view where everything happens in the ocean. The results of our work show that for sockeye, the effect is clearly in the ocean and takes place in the near-shore areas during the first month or so at sea."
Tanasichuk has also found there is relationship between krill abundance and the return of age-three chum. 'It seems to be a type of jacking effect when fish that mature earlier are growing faster....But age-three fish don't make much of the run....the return of four year old fish appears to be determined by the hake fish-eating biomass: the more hake the lower the chum return."
Tanasichuk also can explain variations in West Coast Van Isle wild coho returns. He found that it is biomass of krill longer than 17 mm that accounts for most of the variation in ... coho returns.
He found hake biomass to be in direct competition with first year old herring from Barkely Sound and two year old herring from Georgia Strait as they move out to the west coasts La Perouse Bank where the main summer upwellings occur. In 2005 krill biomass was expecially poor and hake biomass large so he expected herring and salmon stocks to remain low.
However, things have turned around rapidly since 2005. A large body of cold water appeared in the Gulf of Alaska in 2006 and the returned upwellings produced one of the largest plankton blooms ever recorded. In 2006 the green bloom could be seen on satellite to extend from Cape Cook to the mid coast of Oregon and krill began to quickly return. There were so many krill off the west coast in 2007 that the Georgia Strait and Barkely Sound herring which normally summer out on La Perouse Bank, instead stopped at Swiftsure Bank and the mouth of Barkely Sound as there was adequate food. Apparently the cooler water remains in the Gulf of Alaska and explains our cool summer and increases the liklihood of another good ski season. This should be followed with increased ocean survival for both salmon and herring over the next few years.
Jonn Matsen, Squamish Streamkeepers