[env-trinity] CBB: Poor Ocean Conditions For Anadromous Fish To Linger / Warmer Ocean, Smaller Salmon

Fri Mar 11 10:56:38 PST 2016

THE COLUMBIA BASIN BULLETIN: Weekly Fish and Wildlife News

www.cbbulletin.com  March 11, 2016     Issue No. 784

Salmon/Steelhead Returns Forecasted For Another Decent Year; Yet, Poor Ocean
Conditions For Anadromous Fish To Linger

The infamous warm-water ocean "blob" has evolved into a more coastal
phenomenon - the region is now at the trailing edge of a warm El Nino
weather pattern, and the Pacific Decadal Oscillation is in a very warm
period, according to Brian Burke, research fisheries biologist at NOAA
Fisheries' Northwest Fisheries Science Center.

By next year, he said, the physical effects of the El Nino will be gone, but
the warm PDO will likely last a lot longer, as will the poor ocean
conditions, continuing the decline in abundance and nutritional value of
food for salmon.

The so-called "blob" of warm ocean waters has gripped the West Coast and
shaken up its marine ecosystems in the past two years. While that warm water
has cooled somewhat this winter, its effects are now having more of an
impact on systems along the northwest coast of North America.

(See CBB, April 10, 2015, ''Warm Blob' Of Water Off West Coast Linked To
Warmer Temps, Disruption Of Marine Food Web"
http://www.cbbulletin.com/433648.aspx)

The PDO is a pattern of climate variability in the North Pacific identified
by sea surface temperatures.

The warm phase has been in evidence since 2014. Research has shown that when
warm phase PDO settles in, the zooplankton community structure in the
northern California Current becomes more sub-tropical in nature and becomes
dominated by lipid-poor species. This bodes ill for West Coast salmon.

More lipid-rich species are available to provide fatty nourishment for
salmon when water temperatures are cooler.

Burke and other fisheries managers laid out their forecasts for salmon and
steelhead at the Northwest Power and Conservation Council meeting Tuesday.
While ocean conditions will continue to be poor for anadromous fish, the
fisheries managers are predicting relatively good returns in 2016.

Still, while ocean conditions vary from year to year, it seems that the huge
swings in the ocean's impact on the numbers of salmon and steelhead that
return to freshwater may be tempered at least somewhat by better freshwater
habitat and by operations of the Columbia River basin dams to aid salmon.

"I think all of our hard work in the freshwater environment is showing
progress," Bill Tweit, special assistant with the Washington Department of
Fish and Wildlife, told the Council.

"The total returns this year are predicted to be well above average -- not
quite the eye-popping numbers we've seen in the previous years but still
very healthy, driven again by fall chinook," he said. 

The overall return of salmon and steelhead will hit 2.1 million fish, he
said, the eighth highest on record. Last year's total run of 2.9 million
fish was the third highest on record.

Tweit said that optimism for another good year should be tempered with the
understanding that salmon productivity is cyclical depending on conditions
in the ocean, where salmon spend most of their lives. 

"We know things won't stay as good as they currently are, but for now we
certainly are enjoying the harvests and the numbers," he said.

The spring chinook salmon returning to the Columbia River this year entered
the ocean in 2014 when ocean conditions were bad, Burke said. He predicts
that 142,000 spring chinook will return to Bonneville Dam between March 15
and May 31 this year. The fish that entered the ocean one year later, when
ocean conditions were even worse, he said, will return in 2017 when he
predicts a return of 94,000 fish. The returns in each year are still better
than the 10-year average.

Tweit presented to the Council forecasts developed by the US v Oregon
Technical Advisory Committee. Fall chinook salmon again will lead with
returns of 951,200 fish, with 756,300 of those fish upriver fall chinook.
The 2015 return of 1,305,400 fish was the largest since at least 1980. TAC
predicted 925,200 fish would return in 2015.

TAC forecasted the 2016 upriver spring chinook return at 188,800 fish at the
Columbia River mouth. Some 56 percent of the run returned to the Snake River
in 2015, but TAC is forecasting that percentage to be higher this year at 66
percent. In 2015, TAC predicted 232,500 fish would return, but that actual
return of the upriver spring chinook was higher at 289,000. "This year
continues to be above average productivity," Tweit said.

TAC forecasted Upper Columbia River spring chinook at 26,500 fish in 2016,
127 percent of the 10-year average. Wild fish were 15 percent of the return.
The 2015 forecast was 27,500 and the actual return was 37,500, the second
highest return since at least 1979. The 2016 wild forecast is 164 percent of
the 10-year average of 3,000 fish and represents 18 percent of the expected
return.

Upper Columbia River summer chinook are forecasted this year at 93,300 fish,
projected to be the second highest return since at least 1980 and 132
percent of the 10-year average of 70,800 fish. The 2015 forecast was 73,000,
while the actual return was 126,900, a record return since at least 1980. 

After a record number of fish in 2015, the forecast for upper Columbia River
sockeye salmon in 2016 is just 101,600 fish. Last year's forecast was for
394,000 sockeye, but the return was much higher at 512,500 fish. 

Many of the sockeye died in the warm waters of the Columbia River. Returns
to the Wenatchee River with its coldwater refuges fared better than to the
Okanagan River where there are almost no cold water refuges, Tweit said.

Some 265,400 upriver summer steelhead (92 percent of the 10-year average)
will pass Bonneville Dam this year (April through October), compared to the
2015 run of 261,400, Tweit said. The TAC forecast was 312,200 fish, while
the actual run was lower at 261,400.

Wild winter steelhead appear primarily below Bonneville Dam, Tweit said. TAC
forecasts 16,900 fish will return this year to the Columbia River mouth. The
2015 return was 20,100 and the forecast was 16,100 fish.

Columbia River coho salmon reflect ocean conditions along the Oregon and
Washington coasts more than the other salmon species, Tweit said. TAC is
forecasting low returns for 2016 at about 300,000 fish, with about 30
percent of those fish migrating upstream of Bonneville Dam.

The 2015 actual return (171,400) was much less than forecasted (539,600),
which held true for most all Washington, Oregon and California stocks. That
is likely due to ocean conditions that may have effected both juvenile and
adult survival, Tweit said.  Upriver and lower river stocks are equally
impacted.

The 2016 forecast for wild fall chinook at Lower Granite Dam is 12,200 fish.
Forecasted hatchery origin fall chinook is 20,600 fish. The forecast in 2015
was 26,000 fish and the actual passage of hatchery fall chinook at the dam
was 42,000 fish, according to Paul Kline, assistant chief of fisheries at
the Idaho Department of Fish and Game. 

Sockeye, he said, are just half-way home when they reach Lower Granite Dam
on their way to the Stanley Basin in Idaho. Only 10 percent of the 4,000
sockeye that crossed Bonneville Dam actually made it to Lower Granite, Kline
said. The forecast this year is about 750 fish.

Summer steelhead are doing much better. IDFG is still counting wild fish for
the 2015 year, tallying about 33,000 fish. The 2016 forecast is for 49,000
fish, nearly twice the 10-year average of 28,000 steelhead. Hatchery summer
steelhead are forecasted at 98,300 fish this year. The 2015 forecast of
summer hatchery steelhead was 100,000 fish and the actual count was 96,800.

The wild spring/summer chinook count in the Snake River is forecasted to be
18,600 fish, still above the 10-year average of 17,000. The forecast of
hatchery spring/summer chinook is 98,300. The 2015 actual count was 96,800,
while the forecast last year was 100,000 fish. The 2015 return was a
relatively large run of fish, Kline said.

Warmer Ocean, Smaller Salmon: Researchers Producing Data To Better
Understand Reasons, Management Implications

Scientists who study the northern Pacific Ocean are finding some disturbing,
if not alarming trends: the ocean has been warming for several years and
salmon sampled in 2015 from Alaska to California were smaller than normal. 

So says a report by the Northwest Power and Conservation Council on a
meeting last week of the Council's Ocean and Plume Science Management Forum.
Ocean researchers with NOAA Fisheries' Northwest Fisheries Science Center in
Seattle reported their latest findings and discussed the implications with
state and tribal fish managers.

The Council established the forum several years ago to encourage
coordination between ocean researchers and state and tribal fish managers
who produce and protect salmon in the hatcheries and freshwater streams
where they reproduce.

Warmer water affects the types and distribution of food species for salmon -
in general, there is less nutritious food, and that's bad news for juvenile
salmon as they enter the ocean.

At the same time, though, some salmon runs boomed last year, notably those
in Alaska. Others crashed, notably Columbia River coho.

Why?

No one can say with certainty, but research is producing data that will help
further understand the ocean environment and inform salmon management in
fresh water, says the Council account of the forum. 

Laurie Weitkamp, a research fisheries biologist at the Science Center, noted
the apparent effects of the warming ocean on Columbia River salmon: high
returns in 2015 of adult chinook and sockeye, which entered the ocean in
2013 or earlier when the sea was cooler, and low returns of coho adults and
jacks, and chinook jacks, which entered later when it was warmer.

Doug Olson, a supervisory biologist with the Columbia River Fisheries
Program Office of the U.S. Fish and Wildlife Service, said it appears that
when ocean conditions are poor, salmon tend to return in greater numbers as
adults when fewer are released as juveniles.

If this is true, he said, the implication is a huge paradigm shift in
hatchery management, which traditionally focuses on releasing large numbers
of juvenile fish.

He said that if hatchery managers knew two years in advance what ocean
conditions will be, hatchery production could be adjusted - some salmon
spend up to two years in hatcheries before being released to go to the
ocean.

But it is difficult, if not impossible, to predict conditions that far in
advance with much certainty, the scientists said.

There is a lot to learn about all of the ocean and freshwater variables and
how they interact. Models based on ocean indicators developed today may not
be best for predicting future conditions, Weitkamp said.

It could be true that the size and success of salmon in the ocean is
influenced by their sheer numbers and competition for a food base that also
may fluctuate in quality and abundance. But trawl data suggests the density
of salmon in the ocean already is pretty low, which could be the result of
insufficient prey species or some other factors.

"It appears we need to look at this more closely; clearly something is going
on, but we haven't had the resources to look at it in depth," she said.

-- Ocean and Plume Science Management Forum:
http://www.nwcouncil.org/fw/ocean/

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