Possible explaination for missing returns

[victoriaboater]

This happened through my email today; interesting read.

-----------------------------------------------------------------





An interesting comment from a sportfishing forum:

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

 

[Little Hawk]

Howdy,

Thanks V.B. and thanks to John from Squamish Streamkeepers.

Good stuff and good reason to look for improvements in the near future.

We watch and keep our fingers crossed.

Cheers,
Terry

 

[reel easy]

The only explanation for poor returns is DFO blundering, why not wait until the fish actually return to a river system,and not the so called prediction system, before allowing commercial, which includes native, and yes sport fishing to happen. They just can't get it right. Two examples where this system is failing miserably is Alberni and the Fraser.

 

[Dogbreath]

quote:Originally posted by reel easy
The only explanation for poor returns is DFO blundering

Last time I checked well actually any time I've checked the Govt doesn't control the weather.[)]

It's all about Ocean Survival and poor ocean returns aren't the Govt's fault what part of that is hard for you to understand?

 

[alley cat]

Interestingly he last SFAC meeting for Cowichan ,Port Renfrew contained a section on the coho escapement and how late the run was coming in this year.............lots arrived in the second week in November.
Smaller than usual but numbers OK for hatchery breeding purposes and salting of other streams.

AL

 

[chris73]

Here is another interesting article about this. Especially interesting I found the last note by Glen Varney: the salmon appeared starved. That ties in nicely with the article that leads this thread... If that proves true then the main reason for this year's collapse lies within the foodchain and not with fishery quota on salmon as such... Would be interesting to find out if the starvation was at the juvenile age or adult age...!




Few B.C.-born salmon returning to spawn: expertsSHANNON MONEO AND CATHRYN ATKINSON

Special to The Globe and Mail

November 15, 2007

VICTORIA, SQUAMISH -- Salmon returns are down significantly around British Columbia, experts say, with the number of chinook migrating to their birthplace on Vancouver Island falling by as much as 75 per cent and a "collapse" of the chum run in parts of the Squamish River watershed by up to 95 per cent.

At Canada's largest salmon hatchery - the federally run Nitinat River Hatchery on Vancouver Island - 350,000 returning chum have been counted this year compared with 725,000 in 2006.

The chum egg harvest is typically 40 million tiny, glossy orbs.

"This year we'll be lucky if we scrounge up around 15 million," Nitinat employee Glen Varney said.

Nitinat's chinook returns are also hurting, with 8,000 counted this year, down from 14,000 in 2006, said hatchery manager Rob Brouwer.

Instead of harvesting four million chinook eggs, two million will be collected in 2007.

The egg shortfall means that other Vancouver Island hatcheries won't get Nitinat's excess chinook eggs.

One female chinook provides about 4,000 eggs, which are fertilized, incubated, raised to the fry stage and released by the hatchery, which is located in a remote area of south central Vancouver Island.

"When you see a big facility like Nitinat with low numbers, you know there's trouble," said Mr. Varney, who is also director of hatchery operations for the Sooke Salmon Enhancement Society.

In his backyard, a mere 150 male and female chinook were counted in the Sooke River this year. Last year, there were 300, down from about 900 in 2005.

As for Sooke River chum, 25,000 were counted, half of last year's tally.

"There's been a drastic reduction in fish," Mr. Varney said.

Low returns have also affected Fraser River salmon stocks.

The Department of Fisheries and Oceans predicted that 6.3 million sockeye would enter the Fraser this year, but that was slashed to 1.5 million, said Mel Kotyk, director for the department's Lower Fraser division.

During the first Fraser run of the year, only 15,000 of a projected 45,000 sockeye returned to freshwater.

"We need 110,000 to be self-sustaining," Mr. Kotyk said.

And the chum run isn't living up to the expected 1.1 million return, he said.

Along the Squamish River and its tributaries, where hundreds of bald eagles share the returning fish with seals swimming upriver from Howe Sound, chum runs were down by up to 95 per cent. Chinook levels are also significantly lower.

Anglers in the Squamish River system are not allowed to keep any chum that they catch because of the paltry returns.

Brian Klassen, of the Squamish-Lillooet Sport Fishing Advisory Committee, said the DFO issued the non-retention policy for chum in the Squamish, Mamquam, Ashlu, Cheakamus and Elaho Rivers on Nov. 2 "to be proactive." He added that local native groups also drastically cut their traditional fisheries.

"The returns to Tenderfoot Lake are anywhere from 5 to 10 per cent of what we would normally see. The caveat on that is that the run is not over yet, though migration tends to peak by Remembrance Day," Mr. Klassen said.

He added that chum numbers were down around the province, but the Squamish area was the worst hit.

The Mamquam spawning channel, he said, had 700 chum several days ago, but added that in a good year there would be 10,000.

"That's the magnitude of what you are seeing and you're seeing it around the watershed. ... The population seems to have collapsed to a large degree," he said.

The salmon that are not returning went to sea two years ago.

"Something happened in the oceans in 2005," Mr. Brouwer said. "For whatever reason, there was no food."

The salmon Mr. Varney has handled this year appear "starved."

 

[alley cat]

Chris73 , you make a good observation in where did the lack of feed come in their stage of life , I would love to know that answer.

AL

 

[5-Salt Fever]

Same problem down in Oregon as well.

Poor food conditions is the explanation we have been told. I am inclined to believe record harvest level in Alaska has played a roll as well...BC and Wash/Oreg Salmon reported to have wandered further north in search of food.

 

[5-Salt Fever]

Same problem down in Oregon as well.

Poor food conditions is the explanation we have been told. I am inclined to believe record harvest level in Alaska has played a roll as well...BC and Wash/Oreg Salmon reported to have wandered further north in search of food.