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NW Fishletter #392, April 1, 2019
 Ocean Conditions Shift, Tentatively Offering Good News For Future Returns
Young salmon and steelhead heading out to the Pacific Ocean this year are finding cooler water and a healthier coastal environment compared to conditions over the last several years, according to a new report by NOAA Fisheries.
Multiple indicators show that marine conditions are improving along the coasts of Washington, Oregon and California, including better survival of juvenile and adult salmon--particularly coho in the northern part of the system, NOAA researchers said.
While most salmon and steelhead runs in the Columbia River are likely to remain depressed this year, the improved conditions could bode well for future runs, scientists said.
However, there is also evidence that the 2014-2015 ocean heat wave--known as The Blob--is having a lingering impact on the ecosystem, they said.
The agency presented its annual status report on the California Current Integrated Ecosystem Assessment to the Pacific Fishery Management Council on March 7, followed by a media teleconference on March 8. It's the 7th annual report to the fisheries council, which manages fishing for 119 species along the Pacific Coast, ranging from salmon and tuna to anchovies and groundfish.
Jameal Samhouri, a marine ecologist at NOAA's Northwest Fisheries Science Center, said the positive indicators could mean that the ocean is returning to more normal conditions some five years after the Pacific Ocean's longest and most severe heat wave hit, staying put for more than a year.
Scientists are concerned that marine heat waves are occurring more frequently, leaving ocean environments less time in between to recover, Samhouri said. "It's a pattern we're seeing across the world," he added, and then asked, "Is this the new normal, or will it come back to something more like what we saw prior to 2014?"
Brian Burke, research fishery biologist at the Science Center, said the question of whether the ocean will ever return to pre-Blob conditions is one he's heard frequently. His new answer, he said, is that changing conditions appears to be the only constant--and perhaps the new normal--in the Pacific Ocean.
In the last several years, scientists have seen The Blob--which caused major ecological changes ranging from the Pacific's largest toxic bloom of algae to the crashing of key portions of the ocean food web--along with two major El Nino and two La Nina events.
"We can't really count on typical or normal conditions anymore," he said in a March 12 presentation to the Northwest Power and Conservation Council.
Currently, the ocean conditions are close to neutral, which is part of the reason scientists are optimistic about the potential for improved salmon returns next year. However, NOAA's Climate Prediction Center issued an advisory on March 14 stating that weak El Nino conditions have an 80 percent chance of continuing through spring, a 60 percent chance of persisting through summer in the northern hemisphere, and a 50 percent chance of continuing beyond summer.
Chris Harvey, also a Science Center researcher and a lead editor of the report, pointed to several positive indicators in what's known as the California Current Ecosystem in 2018.
The report tracks species up and down the Pacific Coast that are important to the marine food web, as well as climate and ocean conditions, to give the fishery council an idea of the ocean's health and productivity.
According to the report, ocean conditions were close to average in 2018, although a weak El Nino did recently emerge. Copepods off the Oregon coast were predominantly the cool-water northern species rather than the southern species that are smaller and have a lower fat and nutrient content.
"Positive values of northern Copepods in summer are correlated with stronger returns of Chinook salmon to Bonneville Dam," the report said. Scientists also found more anchovies, more sea lion pups, better sea lion pup growth and more fish-eating birds--all indicating improved conditions of the food web last year.
The report included the length of krill sampled off the coast of northern California, as a new indicator. Scientists found a shift in the 2017-2018 krill lengths, which were below average during much of the 2014-2016 ocean heat wave, but were typical of pre-heat wave conditions during wintertime.
"As with copepod community composition off Newport, these results imply more productive conditions for predators of zooplankton over the last two years," the report said.
June surveys of juvenile Chinook and coho salmon off the coast of Washington and Oregon are survival indicators during their first few weeks at sea, and also correlate to returns in later years. The subyearling Chinook catches were close to long-term averages in 2018, and catches of yearling coho were among the highest recorded. "These data suggest that the direct negative impacts of the marine heat wave on salmon survival have subsided," the report said. "However, other aspects of the ecosystem have not completely returned to normal, suggesting that indirect impacts on survival may still occur."
The report also looks at the most recent commercial fishing reports. While the 2018 catch reports are not yet available, in 2017, fish landings increased by 27.4 percent compared with 2016--a 12.3 percent increase in revenues.
Those increases were driven by the Pacific hake, Dungeness crab and market squid. With the exception of hake, landings of groundfish were near historic lows from 2013 to 2017, although 2017 did offer a slight increase. Commercial landings of salmon also declined sharply and remained low over the last several years. Recreational landings for Chinook and coho were near the lowest levels observed in recent decades, the report said.
"Our outlook suggests we are not quite out of the woods," Harvey said during the media conference. He said large numbers of pyrosomes--a warm-water species that increased dramatically during The Blob--continue to be abundant off Washington and Oregon, competing for plankton and inundating fishing gear.
He said 2018 also saw widespread algal blooms in Oregon and California, and extensive hypoxia and acidified water off Washington and Oregon. -K.C. Mehaffey
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