[narrator] The Pacific Northwest s Puget Sound.

Its waters form the nation s second-largest estuary and comprise the southern half of the greater Salish Sea.

With more than 4 million people calling it home, the Puget Sound region is known for its natural wonders both above and below the surface.

[brian] The real beauty of Puget Sound is what lies under the surface.

[narrator] More than two dozen kelp species create an underwater haven for marine mammals, hundreds of fish species, and a diverse array of invertebrates and other organisms.

[betsy] Puget Sound is a biodiversity hotspot.

Kelp forests themselves are fueling, powering, supporting the marine ecosystem and the fisheries on which we depend.

[brian] Everything eats kelp.

It's in the shrimp and the clams and the salmon and the whales.

Kelp is the reason why estuaries are productive places.

[brooke] They are these giant underwater forests that are just totally irreplaceable.

[narrator] Kelp forests have played an essential role in this ecosystem for many thousands of years.

As early peoples migrated into the Americas, a lifeway of kelp beds supported them with food and safe passage on their journey.

Their descendants - known as the Coast Salish - comprise a loose grouping of indigenous nations who still live here.

Kelp plays a significant role in their shared cultures.

[leonard] It s also a very big indicator of the health of the sea and of our ancestral waters here.

[narrator] In recent years, Tribal citizens and Western scientists alike have observed that kelp is in serious decline in some areas.

[tom] We've seen significant losses.

The first maps that we had were done in the 1870s and there was kelp marked all over South Sound.

It's gone.

People are beginning to realize it matters.

It makes a difference.

[casey] Kelp is very important to all marine species.

It's also important to us as humans.

We don't want to think about what happens if we lose it.

If it disappears, it's more than just the kelp that will disappear.

[narrator] Resource managers, scientists, tribal citizens, and advocates across Puget Sound are working together to solve the mysteries of conserving and restoring kelp forests.

What does this region s interconnected history with kelp reveal about its current health?

And how will kelp persist in the future?

[announcer] Major funding for this program was provided by the Batchelor Foundation, encouraging people to preserve and protect America s underwater resources.

Additional funding was provided by the Parrot Family Endowment for Environmental Education.

[narrator] Puget Sound sits at the southern end of the Salish Sea, a complex of waterways spanning more than 270 miles across the US-Canadian border.

Not far from the Pacific Ocean, along the Strait of Juan de Fuca, lies the remote San Juan Archipelago.

Known for its local population of endangered Southern Resident killer whales, the islands are also home to the University of Washington s Friday Harbor Labs.

[brooke] We could check around this bend.

[narrator] It is here that post-doctoral researcher Brooke Weigel is working to uncover the keys to conserving and restoring kelp.

[brooke] Some of the kelp are known as canopy-forming kelp because they grow from the bottom of the ocean all the way to the surface.

I study the bull kelp.

Its scientific name is Nereocystis luetkeana, and it anchors itself to the bottom of the ocean with a portion of the kelp called a holdfast.

And it looks kind of like plant roots, but they're not roots because they don't take up any nutrients.

[narrator] Although kelp are classified as algae and not plants, they are some of the most productive carbon-fixers on the planet.

As primary producers, kelp remove carbon dioxide from the atmosphere via photosynthesis.

[brooke] Kelp are extraordinarily productive.

They fix an immense amount of carbon in coastal ecosystems.

They also grow really fast.

[tom] Kelp makes food more rapidly than almost any other living organism.

You see a kelp plant and the blade, and so forth, and it'll just kind of sit there and it looks like it's just sitting there.

Actually, it's growing all the time and the growth takes place near the base of the blade.

And when it grows, it extends the blade.

And so the plant may not look any bigger, but it's just like this conveyor belt with the end of it falling off.

If it didn't tatter, it would be four to six times longer.

There s a four to six times turnover every year in that plant.

So what you see is only a fourth or a sixth of what you get into the food web.

[narrator] In recent years, researchers have begun to measure just how far kelp reaches into the ecosystem.

[tom] And so things like fish and birds, crabs, amphipods, barnacles - all these things: you can measure how much kelp carbon have they consumed and are made of.

And, it s amazing.

Rockfish on the outer coast are half to three quarters kelp carbon.

Crabs are like 25% kelp carbon.

They don't eat the kelp, but they eat things that eat kelp that eat kelp.

And so that kelp carbon goes up the food web and it ends up in all these different animals.

[narrator] Kelp forests also create structured habitat, providing safe refuge and foraging opportunities for a diverse community of living organisms.

[tom] People have known for a very long time the importance of kelp as habitat.

It wasn't academic science that figured this out.

Native American people knew for a very long time.

You want to go fishing?

And the Samish Tribe, in particular - they know when you go fishing, go find a kelp bed.

That's where the fish are.

[narrator] The Samish Indian Nation is just one of many Coast Salish tribes that understand the tremendous value of kelp, not just as a food source, but also as integral to their culture and definition of home.

[todd] There's not sort of this separation of environment that I have from a Western perspective.

And so for example, with the plight of our resident J pod Orcas, Samish people and other Coast Salish people view them as relatives.

It s not about saving a charismatic megafauna - it's about: what would you do to save your grandparent or your child?

And that lends a very different perspective than I think most Western scientists have thought about very much.

And I know those types of things, working in tribal country, have really opened my eyes and put an additional layer of meaning on the work that I do.

[narrator] In partnership with NOAA and the Northwest Straits Foundation, Todd Woodard and his team are digitizing kelp surveys into an on-going database to better understand the health of kelp in traditional Samish territory.

[casey] The Story Map titled Decade of Disappearance looks at two sets of imagery - one from 2006 and one from 2016 and it compares the bull kelp canopy within the San Juan islands.

And then we've also done kayak surveys out in the islands and we've compared that to our data.

And we are continuing to digitize new imaging to compare to that baseline 2006 data.

[narrator] After digitizing these aerial surveys, the Samish team could see a clear and astonishing decline.

[todd] And so we were noticing about a 30% decline overall, but there's some local places like the Northern Islands - Patos, Sutia, Matia - where we were seeing 75-80% loss in canopy coverage.

[narrator] The team also worked with tribal elders to incorporate Traditional Ecological Knowledge, which includes the stories, traditions, and observations of indigenous peoples over hundreds, or thousands, of years.

[todd] Samish and other Coast Salish people have been stewards of this environment since time immemorial.

And so it adds that depth that tells a much more complete story as to what's happening in the environment.

[narrator] Oceanographer and Samish citizen, Toby McLeod sat down with tribal fishermen to deepen the baseline data with their traditional knowledge.

[toby] I went to my father's house, and my uncle happened to be there, who also fished with my dad.

And I brought out this map that Casey had printed out of the San Juan Islands.

And I just asked him: Where is there kelp now?

Where was there kelp when you were fishing?

And where did you hear of kelp existing historically?

[narrator] As Toby s father drew lines on the map to indicate kelp beds through the years, the two men provided more than 100 years of local fishing knowledge through their oral histories, which was then digitized into the team s Story Map.

[toby] They had stories of fishing everywhere and they had stories that they'd been told by their grandparents of where they used to fish and how they used to fish.

There was kelp out here that he could lay his net alongside and catch king salmon, and then he told me stories about kelp being so thick that his net wouldn't even touch the rocks if he laid it along the beach because of the density.

Not so anymore, but pretty much everywhere in the islands, you could find it.

[narrator] The Samish Department of Natural Resources is not alone in documenting an alarming decline of bull kelp canopy in the Salish Sea.

Marine Ecologist Helen Berry and her colleagues recently completed a study focused on sites much farther South in Puget Sound in the traditional territory of the Squaxin Island Tribe.

[helen] These are really important areas to look at because they're the farthest away from the ocean and the most impacted by humans.

So they're hundreds of miles away.

They're at the very southern terminus of Puget Sound.

[narrator] Helen and her team were able to create a baseline of kelp s presence over more than a century using the principles of historical ecology, which reaches back into the historical record to understand changes over time.

[helen] We first looked for historic records from the time of early European colonization, and that's from the mid-1870s because European settlement happened quite late here.

If you look at any chart, you can see that the mapmakers have carefully delineated where the big kelp beds are.

And the reason they do that is because kelp grows in shallow areas and it attaches to rocks.

And so if you're in a boat, you really want to stay away from the kelp beds because that way you're not going to end up on the rocks.

So that was one of the most important historical uses of kelp, just for transportation, and it's one we've used in more recent years because it's an amazing record historically of where kelp has occurred.

[narrator] Helen also utilized early topographic sheets completed by the U.S. Coast Survey in the late 1800s, a time when less than a thousand people inhabited South Puget Sound.

Early farmers in the area also used kelp as a vital fertilizer.

Her team combed the pages of an almanac identifying historic kelp harvesting locations.

[helen] So we took all of those really diverse information sources.

And then we used spatial geo-databases and GIS - geographic information systems - to combine all that data and analyze it as a single synoptic dataset.

And what we found is in South Puget Sound - one of our areas of greatest concern - the current distribution of bull kelp is about 20% of what it was historically.

So, there's been a big change here.

[narrator] Despite an 80% decrease in the presence of bull kelp nearer the more populated regions of Puget Sound, additional studies found that kelp beds are not necessarily declining everywhere.

[helen] We did a similar study in the Strait of Juan de Fuca, which is the entrance of the Salish Sea, and we found there that the populations are generally stable over the last hundred years.

And so what this really teaches us is that the status of kelp over the last 150 years really varies based on where you are.

It really matters where in the sound you're asking that question.

[narrator] One group that is working to support researchers like Helen Berry across the Salish Sea is the Puget Sound Restoration Fund, or PSRF.

[betsy] Protecting, conserving, understanding, studying, restoring kelp forests is going to take a huge collective undertaking, just because kelp is such a diverse and varied and foundational part of the ecosystem.

[narrator] In 2021, Betsy and the PSRF team organized the first-ever kelp expedition aimed at connecting stakeholders from across the region.

The 8-day expedition included dive and survey locations ranging from the Strait of Juan de Fuca through the Seattle area and all the way down to the state capitol of Olympia at the head of Puget Sound.

[betsy] The kelp expedition became a way to explore kelp forests together with lots of scientists who are carrying on incredible work and with tribes who have really important traditional ecological knowledge, so that we can benefit from this textured knowledge.

[narrator] More than 40 organizations participated in the expedition, including federal and state agencies, university scientists, and local tribes.

In all, 185 people from around the region actively worked together on the water to address the future of kelp in the local ecosystem.

[betsy] The kelp expedition was embraced by all these different partners and individuals.

It was a really beautiful collective experience.

[narrator] In addition to fostering collaboration and creating a network of monitoring sites around the Salish Sea, PSRF is actively working to solve the complex riddle of restoration.

One of the stops on the kelp expedition was the Port Madison Indian Reservation in Suquamish.

Here, PSRF has been working with the Suquamish tribe and with NOAA to rebuild a kelp forest where it existed historically.

[betsy] The reason we got started with kelp in the first place is because tribal leaders told us that it was important because that is a beginning point for fisheries that tribes have depended on for such a long time.

[leonard] Our ancestors and my elders and my dad all talked about the fact that there were thick kelp beds just off the water here in Doe-Keg-Wats, where they were active in fishing and clamming and spending a lot of their time out there.

Those are now gone and restoring those is so important for what we call the near-shore environment of our ancestral waters.

[brian] This site here is one of what we call a historic area of presence.

So there used to be a floating kelp bed there, a kelp canopy, and a lot of that loss has occurred relatively recently.

Noticing that decline is a little bit different from understanding why it's happening and that's still something that eludes us right now.

We can't go to the library and borrow a book about how to do this.

We have to figure out for ourselves the best ways to do that and how to be effective at that takes trial and error.

It takes experimentation, and that's the phase that we're in right now.

[betsy] It is hard and complicated to try to figure out how to restore kelp forests.

You can't just produce and outplant kelp seed, which people know how to do.

They do it all over the world for kelp farming purposes.

What you have to do is not just get that kelp to grow in a single year, but you have to do it at a magnitude and at a scale that it will come back the following year.

[narrator] Back in the San Juan Islands, Brooke Weigel is one of many researchers working to better understand the mysteries of how bull kelp reproduces year after year.

[brooke] Kelp are experiencing many different stressors, but we actually know very little about how these different stressors affect their physiology, their growth, their survival and their reproduction across their life cycle.

[narrator] Brooke begins by collecting the reproductive patches found on kelp blades and bringing them back to the lab at Friday Harbor.

There, she is able to take a closer look at the reproductive cycle under a controlled range of temperatures.

In this study, she s comparing kelp populations from cold water sites in the Strait of Juan de Fuca with warmer water sites near Squaxin Island.

[brooke] Under the microscope, I'm assessing at what temperature fertilization happens and you have reproductive success, because you need to have that completion of the life cycle in order for kelp to survive and persist year after year.

[narrator] Brooke s results suggest what is already being observed across the Puget Sound region: warmer-than-usual summer temperatures seem to be negatively impacting kelp s ability to reproduce.

[brooke] With warmer temperature, the kelp are growing faster, and then they reach a critical threshold at which their cellular processes start to decline and it's too stressful for them.

[brooke] Here s another good one.

[narrator] Research such as Brooke s may have important implications for kelp enhancement projects like the Puget Sound Restoration Fund s site in Suquamish.

[brooke] It's important to know which kelp population to select.

If you're growing kelp and planting them into the ocean, you need to know something about how they might respond to these environmental stressors, like increasing temperatures, low nitrogen concentrations, increasing predation from things like crabs and urchins and other factors that they're experiencing in their environment.

[narrator] While researchers and managers across Puget Sound work to hone our understanding of kelp s life cycle, there is still much to be revealed.

[tom] We've started to see kelp disappear 50, 75, 100 years ago.

It's not something that's all happened here in the last 10 years.

So, there s some place in that circle that s broken and we don't know where that circle, it's broken.

It s still a mystery.

[betsy] There is work ahead, significant work ahead.

So we need to grow the science pretty significantly in order to be effective.

[todd] There's no question that Puget Sound is in trouble.

There are some serious challenges ahead of us, not to mention climate change and sea level rise, but, you know, growth pressures and pollution all are having an effect despite how beautiful this area looks from the surface.

[narrator] As stakeholders work together to understand, conserve, and restore kelp in the Salish Sea, all agree that it is key to the region s abundant and diverse ecosystem.

[tom] We wouldn't have had this conversation five years ago.

We wouldn't have this conversation two years ago.

Kelp is having its moment.

And one of the moments it's having is this bringing together of all these disparate stakeholders, if you will.

All these different people working together on this problem, which is really cool.

[todd] The only way you can make real progress really on any environmental front is to have that network of partnerships and the tribes are a significant part of that.

[helen] We're lucky enough now in Puget Sound to have what I would consider a really unique group of people that are working together.

So government scientists working with the tribes, working with local volunteers, working with academics, we do stand a chance of making a difference.

[leonard] We have to think about what this impact will be on seven generations in the future.

This is something that we may have a chance to preserve today for those future generations.

So when they come in here to fish or swim or dig clams, or pull in our canoes, maybe they'll get their paddles caught up in some kelp beds.

It's very, very important to us, culturally and economically and spiritually as well.

[toby] What we do to the environment we do to ourselves.

And because kelp is such a fundamental part of the nearshore ecosystem, the way that we affect it dramatically affects us as people that live in this area.

[helen] Kelp is an unsung hero of Puget Sound.

So many people see the Orcas, or they see the salmon, or they see the birds, or they see the forage fish.

And to have those amazing resources and animals in our midst, we need to provide them with habitat and we need to support the food web and kelp is critical to that.