The Salish Sea: An imperiled wonder of the Northwest

The Salish Sea stretches almost 400 miles from the southern end of Puget Sound near Olympia, to the northern boundary of the Strait of Georgia in British Columbia. It's easy to take for granted, and a new study suggests we do so at our peril.

Dr. Kathryn Sobocinski is an assistant professor in the Department of Environmental Science at Western Washington University. She's the lead author of a new study looking at the current health of the Salish Sea. She told KUOW’s Kim Malcolm what she learned.

This interview has been edited for clarity.

Kim Malcolm: This report is called State of the Salish Sea. I understand it's been 25 years since the last in-depth look at the health of the Salish Sea. How's the patient doing?

Kathryn Sobocinski: That's a good question. It's a metaphor we use throughout the report. We don't have the perfect instrument for measuring the state of an ecosystem. It took us a very long report to identify and articulate the stressors and impacts on the ecosystem.

The responses to these stressors are not uniform. The fish response will be different than the Orca response, will be different than some invertebrates or maybe phytoplankton. But we can see signs that our species and ecosystem processes have changed in negative ways, and that degradation is outpacing protection and restoration.

It sounds like we are heading in the wrong direction. Can you give us a specific example that proves to you that the health of the Salish Sea is in decline?

I think the best place to start is salmon because they're so iconic in this region. Our salmon populations have declined and not recovered over the last 30 years. Part of that is because of habitat in critical areas that has been lost, both in the freshwater system and the marine system.

We also have contaminants in the marine food web that are persistent, and they're leaving distinct chemical signatures in organisms that live here. Our estuarine water quality has declined. This is things like dissolved oxygen, temperature, our nutrient levels, and ocean acidification is starting to impact calcifying species in the region too. These are oysters and other invertebrates that build their shells with calcium.

Additionally, warming global temperatures are changing freshwater input and the temperature of water within the Salish Sea. These contribute to secondary stressors like marine diseases and weakened immune systems in the organisms living here.

Your study says “The Salish Sea is under relentless pressure.” I'm guessing the humans living within a few miles of the sea continue to have an outsized impact here. Is that right?

I think it's everyone who's living within the watersheds that drain to the Salish Sea. One of our big issues is stormwater pollution and runoff from the area that we all live in. That all flows down into the Salish Sea, where it's impacting marine communities.

And there are more people living here, millions more, than 25 years ago, 100 years ago.

There's been a really long history of seascape change here. Our area was originally inhabited by Indigenous people 10,000 years ago, but it really wasn't until the last 200 years where we've had profound effects on the seascape and landscape interface, especially along the coasts where people live and have built their industry. There's this history of legacy, continuing, and now emerging concerns that are all interacting within the Salish Sea, leading to this overall degradation in the area.

Then we have these larger forces of climate change that your study looks at. What measurable impacts are you seeing there compared to 25 years ago?

When the Shared Waters report was written 25 years ago, climate change and the impacts of climate change were just really starting to get on our radar. In the intervening 25 years, we've really focused a lot on how climate change in the marine ecosystem is influencing us locally. We've seen warming global temperatures that are changing freshwater input and the temperature of water within the Salish Sea.

We've also seeing ocean acidification, and the fact that it's impacting calcifying species in negative ways, they're not able to build their shells because of the increased acidification of our marine waters. We're also seeing sea-level rise. This is an important one because people live in low-lying areas, especially many treaty tribes, and Indigenous First Nations people occupy these lower-lying areas. They're really at the forefront of climate adaptation plans, trying to figure out what to do about the fact that our changing climate is impacting them in negative ways.

It’s hard to hear about all of these things stressing the health of the Salish Sea. I can only imagine how hard it is for you and your fellow researchers to keep documenting this year after year. When you think about what needs to be done, what kinds of solutions are you looking to to get the health of the sea back on track?

The kick here is that we have really great science in this region, and we need really great science to identify our problems. But the solutions tend to be largely policy-driven, not science-driven. This report was essentially a synthesis of the science in the region, but the next step would be to develop policy and regulatory structures that would lead to more protection of this ecosystem.

Recognizing the Salish Sea as an ecosystem, beyond the political borders, is really imperative. The organisms living here move freely back-and-forth across the international and territorial borders, but we still are stuck in this policy arrangement that treats this as a divided ecosystem.

As we're a growing population, we also need to consider development in ways that are having less impact on our marine waters and proactively address problems like stormwater runoff and the associated pollution with it.

We also have insufficient wastewater treatment and destruction of critical habitats like eelgrass, kelp, and river deltas, where a lot of our organisms live out the early part of their life.

What’s the most important thing you want to leave with us about why this matters?

I think we value the Salish Sea as an ecosystem. We get some aesthetic enjoyment out of it being in our backyard. Many people like to go fishing or boating, or just down to the beach to stare out on the water after a long day at work. But beyond that, it also serves to mediate our climate and provide habitats for species that historically had been taken for food resources.

This area is also really important to the Indigenous peoples living in this area, some of which have treaty rights to salmon and other species. They've relied on the Salish Sea for generations. I think it's important not to undermine that in this conversation.

Listen to the interview by clicking the play button above.