Category: Salmon

Prey and predators create varying life-or-death conditions for salmon, as shown with Atlantis model

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This article is the latest in a series about computer models and their uses within the Puget Sound ecosystem. As scientists uncover more and more information about a particular ecosystem, computer modelers are often eager to put that raw data to good use in complex models tuned to local conditions. One highly acclaimed model, called Atlantis, has been applied to more than 40 ecosystems around the world. In Puget Sound, Atlantis has been used to study the food web to determine whether salmon are more threatened by predators or by […]

Examining the link between low summer stream flows and climate

Low stream flows in a tributary of the Skykomish River. Photo by Jeff Rice.
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A 2023 paper in the Journal of the American Water Resources Association says future low flows in Puget Sound streams could be lower than are projected by climate models that do not reliably account for multidecadal climate variation. The paper is co-authored by Nicholas Georgiadis and Joel Baker of the Puget Sound Institute. When rains finally returned to Puget Sound last fall, they provided welcome relief for spawning salmon. Drought conditions had left streams at record lows, causing many creeks to become dangerously warm for fish, and in some cases […]

Southeast Alaska troll fishing restored for this year by court of appeals pending full legal review

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Fishing in Southeast Alaska by the commercial troll-fishing fleet will not be cancelled this year, as ordered by a Seattle judge, thanks to a last-minute ruling by the U.S. Ninth Circuit Court of Appeals. Considerations for the economic damage that would be caused by shutting down the Alaskan fishery outweigh the “speculative environmental threats” that led the lower court to effectively close the fishery, according to the appeals court order. The heart of the legal battle — how fishing for Chinook salmon affects the endangered Southern Resident orcas — remains […]

Health of killer whales examined through Bayesian network modeling and informed predictions

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As part of a project exploring the technical uncertainties surrounding Puget Sound water quality, we are reviewing how computer models are used to advance our understanding of natural systems. This blog post is part of a series focused on different models and their uses within the Puget Sound ecosystem. The project is jointly sponsored by King County and the Puget Sound Institute. Qualitative network modeling, as shown in the previous post in Our Water Ways, is focused on actions that create either positive or negative results for actors in the model. […]

Shutdown looms for Alaska summer troll fishery; court order aims to provide more salmon for orcas

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Southern Resident killer whales, which frequent Puget Sound, are expected to benefit from more Chinook salmon later this year, as expressed in a court order calling for the suspension of a major troll fishery in Southeast Alaska. Alaska state officials are dismayed by the ruling, saying that closing this commercial fishery would have a devastating effect on fishing families in Alaska and on many small communities along the coast. The state has launched an appeal of the ruling. The court order, signed last week by U.S. District Judge Richard Jones […]

As winter approaches, salmon and orcas are still a commanding presence

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With salmon and orcas still on the move and facing ever-changing weather conditions, I thought it might be time for a brief update to my blog post of Nov. 21. At the time of the last report, the Puget Sound region had gone through a 13-day dry spell, which followed a period of brief and limited precipitation. Low stream flows were making it tough for chum and coho salmon to go upstream when they should have been at their peak of spawning. Many unfortunate fish were dying before they could […]

Low rainfall leads to an odd and changing year for salmon, killer whales and people

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It has been an interesting year for observing the behavior of Southern Resident killer whales, chum salmon and humans in the Puget Sound region. Weather played a significant role. Two weeks ago, all three pods of endangered orcas spent four days together in Puget Sound, something we have not seen in years. Chum salmon, which the whales feed upon in the fall, appeared to be on a stop-and-go migration schedule because of the unusual rainfall pattern. And, as always, the activities of people must be noted within this ecological context. […]

Lawsuit seeks to block Southeast Alaska troll fishing to increase salmon for orcas

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How much should Alaskan fishing be curtailed to provide more food for the endangered Southern Resident killer whales? It is an important question, enmeshed in conflicting federal priorities and provoked by a lawsuit brought by Wild Fish Conservancy, a Seattle-based conservation group. A federal court ruled in August that the National Marine Fisheries Service had violated the Endangered Species Act and the National Environmental Policy Act in its approval of salmon harvests in the Southeast Alaska troll fishery. That fishery harvests Chinook salmon originating from streams as far south as […]

Scientists dig into massive data collected during international high-seas expedition

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Questions about where salmon go and how they survive when traveling far out into the Pacific Ocean have puzzled scientists for 200 years. But a new vision for piecing together this intricate puzzle has begun to emerge, thanks to sophisticated research tools deployed during an international expedition this past winter. Last week, scientists got together in Vancouver, British Columbia, to share their preliminary findings and to brainstorm the next steps in a collaborative effort to solve some of the great mysteries of Pacific salmon. Researchers from multiple countries provided wide-ranging […]

Killer whale census shows another down year, with three deaths and two births

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Three deaths and two births. Over the past year, the endangered Southern Resident killer whale population has declined by a total of one, according to the annual census report submitted yesterday by the Center for Whale Research. Now the number of whales in all three pods stands at 73, down from 74 last year and declining from 98 animals the past 25 years. The births of J59 last February and K45 in May have been widely reported, along with the death of the much-loved K21, a 35-year-old male named Cappuccino. […]

Add-on structure will begin to address steelhead crisis at the Hood Canal Bridge

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The Hood Canal Bridge, which connects the Kitsap and Olympic peninsulas, has proven to be a dangerous impediment to juvenile steelhead trout. As many as half of the young migratory steelhead in Hood Canal may get picked off by seals, birds and other predators as the fish try to pass under the floating highway, according to studies. While a permanent solution may be years away, the first step at reducing predation at the bridge may be just around the corner, as construction crews prepare to fabricate a floating structure that […]

New film about spring Chinook delves into history, culture and science in unique habitats

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A new film, titled “The Lost Salmon,” opens with a video montage that takes us through some wondrous scenes: A wide aerial shot of California’s majestic Salmon River, moving to an underwater view of salmon swimming through the clear water and then to an action spectacle of wild salmon practically flying through the air to surmount a rushing cascades. The filmmaker, Shane Anderson of Olympia, merges passion, culture and science in this documentary that premieres tomorrow on public television. The project culminates years of investigation and filming, as Shane follows […]