Author: Christopher Dunagan

Puget Sound ecosystem holding on, but recovery remains uncertain, says latest status report

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Efforts to restore ecological health to Puget Sound have largely failed to meet recovery goals, yet fish and wildlife populations are still hanging on, according to a new report that describes many struggling populations as neither increasing nor decreasing to a significant extent. The latest State of the Sound report, released last week by the Puget Sound Partnership, reveals the ongoing difficulty of recovering the Puget Sound ecosystem in the face of rapid population growth, climate change and a legacy of pollution and habitat damage. Yet the report, produced every […]

A no-death census year for Puget Sound’s orcas, with observations about a recent shift to more female births

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For the first time since Census Year 1993, no deaths were reported this year among the Southern Resident killer whales, which frequent Puget Sound, according to the official census report. Two new births were reported among the whales, increasing the population from 73 to 75. I would also like to share some potentially hopeful information about what appears to be a shift in the male-to-female ratio at birth. While worthy of note, the finding of no deaths may be more a coincidence of the census calendar than a suggestion that […]

What may be the nation’s largest estuary seems hidden in plain sight for many people

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What is the largest estuary in the United States? This is a question loaded with confusion and open to interpretation, as you will soon see. Before we get to the likely answer — which may surprise you — let me share a few authoritative views on the subject: Chesapeake Bay Foundation: “Chesapeake Bay is the largest estuary in the United States and the third largest in the world. It is about 200 miles long and holds more than 18 trillion gallons of water.” U.S. Rep. Derek Kilmer of Washington state: […]

Warm ocean waters work their way into Puget Sound

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Unusually warm waters in the Pacific Ocean — now pushing up against the Washington coast — are keeping oceanographers on alert for changes that could reverberate through the food web, potentially affecting fish, birds and marine mammals in coastal waters and in Puget Sound. Rising ocean temperatures may be related to recent sightings of warm-water fish not usually seen in the Northwest, including a bluefin tuna that washed up on Orcas Island and large schools of mackeral observed in the Strait of Juan de Fuca. Worrisome levels of domoic acid, […]

Two new baby orcas with no deaths over the past year could make for a remarkable census

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This year’s census for the Southern Resident killer whales apparently will document two new calves but no deaths for the 12-month period ending July 1. According to my unconfirmed records, this will be the first time in nearly 30 years that no deaths will be reported in the annual census update. Consequently, the overall population for the three orca pods rises from 73 in 2022 to 75 in 2023. These numbers won’t be official until the Center for Whale Research submits its annual report to the federal government sometime before […]

Salish Sea Model tracks pollution, currents and climate change

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This article is the latest in a series about computer models and their uses within the Puget Sound ecosystem. Today, we look at the Salish Sea Model, one of several models in the region helping to predict water circulation, water quality and food-web relationships. Read the full series: Where and how the water moves The waters of Puget Sound contain complex chemical mixtures arising from natural and human sources. The waters are blended and pushed around by currents and other physical forces, creating conditions that vary from place to place. […]

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 […]

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 […]

Quantitative models, including Ecopath, take food web studies to a higher level of analysis

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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. In the early 1980s, NOAA scientist Jeffrey Polovina and fellow researchers at the National Marine Fisheries Service in Hawaii developed what they called the Ecopath model, designed to describe […]

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. […]

Researchers use a qualitative network model to test ways to boost production at shellfish farms

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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. The skeletal beginnings of nearly all models is a conceptual understanding of the basic workings of the system being studied: Who are the important actors, and what are their […]

Before supercomputers, a structural model helped scientists predict currents in Puget Sound

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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. One of the first working models of Puget Sound was a scaled-down concrete reproduction of the regional topography, with actual water running through channels, around islands and into bays, […]