New studies aid kelp conservation
Bull kelp is easily recognized by its wavy leaves and long, floating stipes that sometimes wash ashore like slimy green bullwhips. In that sense, it is one of the more familiar types of seaweed in Puget Sound. But as kelp forests decline throughout the region, scientists are finding that there is much about this increasingly rare species that remains a mystery.
Betsy Peabody stood in the bow of a small work skiff as it motored out of the Edmonds marina, a few miles north of Seattle. Behind the wheel, Dan Lomax, a biologist with NOAA, peered around her so he could steer. He was aiming for a flotilla of other small boats just north of the floats and buoys that mark the Edmonds Underwater Dive Park. He swung in among them and cut the engine. Peabody leaned over the bow and called out to another NOAA boat: “How’s it going so far?”
“Good,” the driver called back. “We’ve already got divers in the water.”
“Great!” Peabody said. In the distance a couple of paddleboarders were casting off from shore. “And Jodie and Hilary are on their way now,” Peabody said, leaning on the gunwale. In the water below, blades of bull kelp drifted in the lapping waves under a brilliant summer sky. Elsewhere, the bulbs that keep kelp afloat broke the water’s surface here and there. Peabody glanced down, following them as they traced the size and extent of the kelp bed. “It’s not the biggest in the world,” she said. “But it’s not nothing.”
As the executive director of the Puget Sound Restoration Fund (PSRF), Peabody had come to Edmonds with a group of federal and state biologists for the fourth day of a seven-day expedition she organized. Starting at sites on the north coast of the Olympic Peninsula, she and her collaborators would work their way south, hopscotching from kelp bed to kelp bed. In so doing, they hoped to highlight the importance of kelp in the Salish Sea, where its critical role has perhaps been unappreciated—or, given its submerged nature, unnoticed—even as it disappears.
Disappearing bull kelp
More than twenty species of kelp live in the Salish Sea, but say the word kelp and the image that most likely springs to people’s minds is bull kelp. The largest of the kelps here, it is bull kelp that forms the celebrated kelp forests. A single bull kelp can grow more than one hundred feet tall, its thick stipe rising like a tree trunk from a holdfast on the seafloor, before ending in the broad blades that sprout from its bulbous float. These massive structures last only a year, however, unable to withstand the waves and storms of fall, before growing back the following spring.
Although bull kelp isn’t faring especially well throughout the Salish Sea, the species’ disappearance is most pronounced in the central and southern reaches of Puget Sound. There, one paper documented an 80% decline over the past fifty years. In some places entire forests of bull kelp have vanished.
To lose kelp is to lose not only kelp, of course, but also the wide range of species that depend on it: rockfish, salmon, forage fish, marine mammals like seals, sea lions, gray whales. (Many of these species are among the Puget Sound Partnership’s Vital Signs for Puget Sound health which will also include kelp after 2022.) Kelp’s presence in the food web is varied and diverse—even for humans. “You are what you eat, and people eat a lot of kelp, even if we don’t know it,” says Jodie Toft, the deputy director with PSRF (and one of the paddleboarders). “You eat ice cream, you’re eating seaweed.” (Kelp, along with other seaweed, can be used as a thickening agent in ice cream and other foods.)
What exactly drives the kelp’s decline is not known. “Everyone has their feelings about what’s causing it,” said Hilary Hayford, the habitat research director with PSRF (and the other paddleboarder). It could be increasing temperatures (water, air), chemical pollution, oxygen levels, pH changes due to ocean acidification, and so on. Hayford’s vote, “admittedly non-expert,” is that the main problem relates to temperature. “Higher temperatures increase stratification of the water column, which can lead to poor nutrient-mixing and a hot top layer, which is tough on kelp,” she said. “But I would guess a lot of causes are at work.”
In response to kelp’s widespread declines, a consortium of state agencies, tribal governments, and conservation groups released a recovery plan for kelp in Puget Sound in the spring of 2020. The plan’s strategic goals are broad: to understand and reduce kelp stressors; to describe kelp distribution and trends; to restore historical kelp beds; to deepen the understanding of kelp’s importance in the Salish Sea ecosystem; and so on.
In that breadth, the goals speak to the lack of basic information. “That’s the biggest issue,” Peabody said. “It’s why it’s so important to have our own kelp conservation infrastructure here in the Pacific Northwest, rather than the more scattershot approach we have right now.” A lot of what is known about kelp’s decline, she notes, is anecdotal—people remembering where kelp used to be, rather than documented surveys. While such knowledge is invaluable, managers would like to see more systematic approaches, and as a model, Peabody cited California, with its established and robust monitoring programs.
Those programs took years to develop, said Dan Abbott, the director of the Kelp Forest Program for ReefCheck, a non-profit conservation group based in Marina Del Rey, California, that promotes stewardship of reef habitats. Having worked in California and Oregon, Abbott was at Edmonds as a guest diver. “In Washington, there hasn’t been a lot of systematic work on kelp, in part because so many different agencies are doing different things,” he said. “People, in general, know more about icebergs and coral reefs than they do about kelp, even though it’s right here in front of them.”
The Edmonds bull kelp bed, modest in size though it may be, is one of what may become one of ten kelp index sites in Washington. The hope is that the monitoring of such sites will be both a yearly undertaking and more streamlined.
If such monitoring efforts look anything like what was happening at Edmonds, a lot will be going on. As Peabody presided, a film crew was flying a drone out of a speedboat, getting the bird’s eye view of the assembled scientists for a later documentary on kelp in the Salish Sea. Perched on their paddleboards, Toft and Hayford collected samples of kelp blades for genetic analysis; these they dropped off with Peabody before paddling back to shore. Kayakers from the Washington Department of Natural Resources (DNR), meanwhile, had also fanned out. They bobbed in the sound with instruments dangling beneath them, aiming to get a picture of the basic environmental conditions: pH, temperature, salinity, other metrics. “They’re also looking for microplastics,” Peabody said. “They adhere to blades and other structures on a piece of kelp. Often, you can find more microplastics within a kelp forest than without.”
Other than Peabody, the personnel who stayed the longest were the divers from NOAA and PSRF. The PSRF divers were focused on the diversity of aquatic invertebrates; the NOAA divers, on what Kelly Andrews, a NOAA biologist, said was “the fish picture.” Kelp not only provides shelter and refuge for a variety of commercially important species but indirect sustenance. Many species of invertebrates—isopods, amphipods, copepods, other crustaceans, such as crabs—feed on kelp detritus. They in turn become prey for Pacific herring, juvenile salmon, rockfish, or lingcod, among other things. Forage fish can in turn become prey for adult salmon. All of them revolve around kelp, at least for a time.
“The kelp understory is dense,” Andrews said. “You can see a lot of kelp on the surface—the canopy—but there’s even more down below.” Most of the fish the divers were counting were rockfish birthed in the past few months. Andrews was interested in comparing growth rates of rockfish found in kelp to those in eelgrass. It was also an opportunity for the dive team to adapt to new COVID protocols; and in addition to the divers, and perhaps as a sign of things to come, one NOAA biologist had deployed a new remotely operated vehicle, which whirred about at different depths.
Throughout the afternoon, heaping coal trains rumbled past from time to time on the shore. For Peabody, their presence threw into sharp relief the challenge kelp was up against. “Once you’re talking temperature, you’re talking about things being climate-driven,” she said, something that greenhouse gas-spewing coal only aggravates. Climate change is one of the greatest threats to bull kelp in the Salish Sea and beyond. Kelp forests grow best when the water is cold, and temperature stress makes them more vulnerable to other stressors, like disease. “When you’re talking climate,” Peabody said, “you’re talking about solutions that become harder to fix at the local level.”
Rethinking the 'kelp highway'
Peabody first thought about organizing a kelp expedition several years ago. She had done something similar with Olympia oysters, and Leonard Forsman, the Tribal Chairman of the Suquamish Tribe, had suggested the PSRF look into restoring kelp forests; some of the places he had fished before, having lost their kelp, were no more. “It got me thinking of a way to show how integral a resource like kelp is,” Peabody said. “The story of kelp is fundamental to the human story in the Salish Sea.”
Originally, Peabody called the expedition Following the Kelp Highway. The framing stemmed from a 2007 paper in The Journal of Island and Coastal Archaeology. In the paper, the authors—a mix of marine ecologists and archaeologists—argued that kelp forests had facilitated the peopling of the Americas thousands of years ago. Stretching more or less unbroken in the nearshore environment from northeastern Asia across Beringia and down to what is now Baja California, kelp forests provided a readymade route south along the North Pacific Coast. “With reduced wave energy, holdfasts for boats, and productive fishing,” they wrote, “these linear kelp forest ecosystems may have provided a kind of ‘kelp highway’ for early maritime peoples colonizing the New World.”
Peabody liked the image the Kelp Highway Hypothesis conjured: of people flowing down the continent, following a vast kelp biome that both drew and sustained them in their journeys. But when she was talking with Jeff Dickison, the Assistant Natural Resources Director for the Squaxin Island Tribe, he pointed out that analogizing a kelp forest to a highway was, at best, unfortunate; and historically, forests and highways have not gone well together. To liken kelp forests to highways, he said, also placed the emphasis on transport and transience. But not everyone was constantly on the move. Along the way, many peoples stopped. They built communities, settling in, establishing roots (or holdfasts). These people did not think of kelp as a highway. Instead, they thought of kelp as part of their home.
“Yes, people were moving and so you can ask the question, Why did they move?, and kelp is part of the answer,” Peabody said. “But another question, which I think is equally important, is what made people want to stay in a place?” In this, there was a need for a newer metaphor. For Peabody, incorporating that lived-in element is critical to advancing the kelp restoration efforts she has at places like Doe-Kag-Wats and Jefferson Head, on the Kitsap Peninsula. “You don’t just rebuild elements of marine systems, you rebuild the communities around them, too,” she said. “We want to create and recreate a community around kelp.”
As afternoon tuned to late afternoon the DNR kayakers paddled back to the marina, and the NOAA divers were finishing up their transects. Sitting now in the bow of her boat, Peabody mused about what the rest of the expedition had in store. After spending the first three days at kelp beds on the northern coast of the Olympic Peninsula, she and her team would continue south, first to Doe-Kag-Wats across the Sound, on the Suquamish Tribe’s Port Madison reservation, then to the Seattle waterfront, and finally to Squaxin Island, where they would do surveys in partnership with the Squaxin Tribe. The expedition was slated to end with a celebration (and feast of kelp-related foods) in Olympia. “That will be a nice summation,” Peabody said.
The sun was still high and Peabody was feeling reflective. Bubbles were rising from where the divers were. “I love the way the world shrinks during an expedition,” she said. “This sense of total immersion is so valuable when you’re trying to understand something like a kelp forest.” To see a patch of kelp on the surface, she went on, is to glimpse only a hint of its full significance. Just below is a forest the primary productivity of which rivals a tropical ecosystem. Some species grow as much as five inches per day, outpacing even the famously productive phytoplankton. As an ecosystem engineer, kelp provides vital refuge, habitat that supports diverse food webs within its stipes, while also helping to improve water quality. Despite all this, it can be hard, for the terrestrial observer (or even the one on a boat), to feel an appropriate level of reverence.
The key, Peabody said, is not to bring those two worlds together—the one above and one below—but to show how they have never been separate. “I’m hoping this is a catalyzing moment, so that, moving forward, we can learn in a bigger way and do what we need to do,” she said. “Kelp doesn’t just exist in places where you can put it on a map.”