Tag Archives: noaa

Survey Finds Good Krill Numbers Again Off Oregon, But Even More Pyrosomes

An annual spring survey off the Northwest Coast came up with some good and bad news for key stocks.

Krill — hugely important near the base of the ocean food web — and young Dungeness crab numbers were as high as they’ve been in some time, but there are even more pyrosomes off Oregon’s Central Coast and to the south than last year.

RESEARCHERS CALLED THE RETURN OF KRILL TO THEIR SAMPLING NETS “A WELCOME SIGHT SINCE THESE IMPORTANT FORAGE HAVE LARGELY BEEN ABSENT OVER THE PAST COUPLE YEARS SINCE THE ANOMALOUS WARMING” FROM THE BLOB. (NWFSC)

Jennifer Fisher, fresh off a 10-day survey between San Francisco Bay and Newport, reported the findings on the Northwest Fisheries Science Center blog.

“These are the most Dungeness larvae and juveniles we’ve collected in a long time, and we have not seen krill numbers like this since before 2015,” Fisher followed up via email.

That year, 2015, was the height of The Blob — the huge pool of warmer than usual water in the Northeast Pacific that messed things up at sea and on land — and it was also a year after pyrosomes first began to be found in our coastal waters.

By last year, the tropical gelatinous, sea-pickle thingies that are actually colonies of organisms were clogging fishing gear off our coast and even turned up as far north as the rim of the Gulf of Alaska, also a first.

While rockfish were observed feeding on pyrosomes, it’s not clear how their numbers will affect the food web. Another NOAA blog from last October states, “At this point, there are more questions than answers.”

But the May survey answered the question whether they’re still out there.

“The pyrosome catches appear slightly larger and the colonies are larger compared to last year,” reports Fisher.

They can be found starting about 10 miles off the coast, living on the bottom during the day and rising to the surface at night.

PYROSOMES FILL A COOLER ABOARD THE NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION’S VESSEL, THE BELL M. SHIMADA. (NWFSC)

The Science Center will soon conduct another closely watched spring survey, collecting information on young Chinook and coho off Oregon.

Last year’s produced very low catches while one a couple years ago found very small fish. But the resurgence of krill is a hopeful sign that the food web could be rebuilding coming out of the hangover from the Blob.

Fisher also reported on Science Center’s blog that copepods are in a state of flux between winter warm-water communities and summer, cold-water ones that come with the upwelling.

So what does it all mean?

“The krill is a good sign, but the pyrosomes are not, since they are indicative of warm water,” she says. “And the transitional copepod community is also not a great sign for salmon. But it’s still early in the summer upwelling season, so things can certainly change.”

Expanding North Pacific Orca Pods Could Be Driving Down Chinook Size

THE FOLLOWING IS A PRESS RELEASE FROM THE UNIVERSITY OF WASHINGTON

The largest and oldest Chinook salmon — fish also known as “kings” and prized for their exceptional size — have mostly disappeared along the West Coast.

That’s the main finding of a new University of Washington-led study published today in Fish and Fisheries. The researchers analyzed nearly 40 years of data from hatchery and wild Chinook populations from California to Alaska, looking broadly at patterns that emerged over the course of four decades and across thousands of miles of coastline. In general, Chinook salmon populations from Alaska showed the biggest reductions in age and size, with Washington salmon a close second.

NO DOUBT ABOUT IT, ANGLERS AND COMMERCIAL FISHERMEN LIKE TO CATCH BIG CHINOOK — JOEL NYMEYER CAUGHT THIS 40-POUNDER IN THE SAN JUANS A COUPLE SEASONS AGO — BUT HARVEST PRESSURE IS HARDLY THE ONLY REASON THE SALMON SPECIES APPEARS TO BE GETTING SMALLER OVER TIME. A NEW UNIVERSITY OF WASHINGTON STUDY SAYS IT’S DUE TO COMPLEX INTERACTING FACTORS, AND RESEARCHERS HYPOTHESIZE THAT EXPANDING KILLER WHALE POPULATIONS IN THE NORTH PACIFIC ARE TARGETING BIG CHINOOK TO MEET THEIR DIETARY NEEDS. NYMEYER HOOKED HIS KING NEAR POINT ROBERTS WHILE TROLLING A HERRING BEHIND A FLASHER. (YO-ZURI PHOTO CONTEST)

“Chinook are known for being the largest Pacific salmon and they are highly valued because they are so large,” said lead author Jan Ohlberger, a research scientist in the UW’s School of Aquatic and Fishery Sciences. “The largest fish are disappearing, and that affects subsistence and recreational fisheries that target these individuals.”

Chinook salmon are born in freshwater rivers and streams, then migrate to the ocean where they spend most of their lives feeding and growing to their spectacular body size. Each population’s life history in the ocean varies, mainly depending on where they can find food. California Chinook salmon tend to stay in the marine waters off the coast, while Oregon and Washington fish often migrate thousands of miles northward along the west coast to the Gulf of Alaska where they feed. Western Alaska populations tend to travel to the Bering Sea.

After one to five years in the ocean, the fish return to their home streams, where they spawn and then die.

Despite these differences in life history, most populations analyzed saw a clear reduction in the average size of the returning fish over the last four decades — up to 10 percent shorter in length, in the most extreme cases.

These broad similarities point to a cause that transcends regional fishing practices, ecosystems, or animal behaviors, the authors said.

“This suggests that there is something about the larger ocean environment that is driving these patterns,” Ohlberger said. “I think fishing is part of the story, but it’s definitely not sufficient to explain all of the patterns we see. Many populations are exploited at lower rates than they were 20 to 30 years ago.”

It used to be common to find Chinook salmon 40 inches or more in length, particularly in the Columbia River or Alaska’s Kenai Peninsula and Copper River regions. The reductions in size could have a long-term impact on the abundance of Chinook salmon, because smaller females carry fewer eggs, so over time the number of fish that hatch and survive to adulthood may decrease.

There are likely many reasons for the changes in size and age, and the researchers say there is no “smoking gun.” Their analysis, however, points to fishing pressure and marine mammal predation as two of the bigger drivers.

Commercial and sport fishing have for years targeted larger Chinook. But fishing pressure has relaxed in the last 30 years due to regulations to promote sustainable fishing rates, while the reductions in Chinook size have been most rapid over the past 15 years. Resident killer whales, which are known Chinook salmon specialists, as well as other marine mammals that feed on salmon are probably contributing to the overall changes, the researchers found.

“We know that resident killer whales have a very strong preference for eating the largest fish, and this selectivity is far greater than fisheries ever were,” said senior author Daniel Schindler, a UW professor of aquatic and fishery sciences.

While southern resident killer whales that inhabit Puget Sound are in apparent decline, populations of northern resident killer whales, and those that reside in the Gulf of Alaska and along the Aleutian Islands, appear to be growing at extremely fast rates. The paper’s authors propose that these burgeoning northern populations are possibly a critical, but poorly understood, cause of the observed declines in Chinook salmon sizes.

Scientists are still trying to understand the impacts of orcas and other marine mammals on Chinook salmon, and the ways in which their relationships may have ebbed and flowed in the past. It may not be possible, for example, for marine mammals and Chinook salmon populations to be robust at the same time, given their predator-prey relationship.

“When you have predators and prey interacting in a real ecosystem, everything can’t flourish all the time,” Schindler said. “These observations challenge our thinking about what we expect the structure and composition of our ecosystems to be.”

Co-authors are Eric Ward of NOAA’s Northwest Fisheries Science Center and Bert Lewis of the Alaska Department of Fish and Game.

This study was funded by the Pacific States Marine Fisheries Commission.

Feds Issue Early Warning About 2018-19 Columbia Salmon Runs

As if I wasn’t depressed enough about what feels like an even worse return of Puget Sound pinks than forecast, federal fishery managers pushed out an early warning we could see diminished Columbia River salmon runs in coming years.

NOAA says that this year’s annual longterm ocean surveys off the Northwest Coast turned up some of the lowest numbers of juvenile Chinook and coho seen in the past two decades, which could translate into “lean times” in 2018 and 2019.

(NOAA)

The “highly anomalous conditions” observed off Oregon and Washington also included low catches of baitfish, which may mean predators higher up the food chain focused more on salmon smolts — a result seen with murres outside San Francisco Bay and possible but unproven here.

They say that though the ocean has cooled from the Blob, “the biological responses to these warm waters are likely to be evident for a longer period.”

Indeed, high numbers of southern visitors are still being seen.

Surveys showed Pacific pompano catches peaked in 2016 and declined this year but are still well above where they were between 1998 and 2013, while 2017’s jack mackerel catches were the highest ever. Pyrosomes also invaded this spring and researchers report a “complete shift” in the predominate jellyfish species off the coast.

The Daily Astorian has been working the ocean beat hard this summer, and broke this news earlier this week. In a report yesterday, the paper said the tuna season has been “abysmal” so far, with boats having to go 125 miles or further out to find fish, though the albies have been nice and fat.

The caveat in my case is that, while I’ve been fishing two spots — my local beach and the Duwamish in Tukwila –without success, that doesn’t mean the salmon are necessarily not there, though the lack of jumpers certainly is suggestive.

Similarly, scientists need to take a deeper dive with what they’ve initially collected and compare it to other data before they issue 2018 Columbia salmon forecasts.

“Our results are still in the preliminary stage, with several next steps,” reads a mid-August memo to Michael Tehan, NOAA’s Assistant Regional Administrator at the Interior Columbia Basin Office in Portland. “Zooplankton and salmon samples that we collected at sea still need to be processed to estimate important biological metrics, such as copepod biomass, salmon condition and stomach contents, and salmon growth hormone levels. All results will be placed into a broader context by integrating them with oceanographic data derived from satellites and ocean buoys. We will also corroborate our results with other coastal ecosystem surveys (e.g., Gulf of Alaska) that regularly catch Columbia River salmon. Finally, each year we synthesize results of this work, including an estimate of adult salmon returns to the Columbia River.”