ABOARD THE CHINOOK, northwest of Burrows Island — A pair of kayakers paddle mostly silent in the water not far from Anacortes, shouting back to their lead boat every so often and tracking their position around the bull kelp bed with a satellite monitor.
The kelp collects in bunches near the surface, the bed hugs the shoreline of the island and sways with the current. This is just one of the many beds watched closely by the Samish Indian Nation and mapped out yearly using aerial footage and GPS data to show just how fast bull kelp is disappearing throughout the San Juan Island archipelago.
The Samish are seeing perhaps a 30% decline over the past couple of decades, said Todd Woodard, executive director of the tribe’s infrastructure and resources. Move south, and the numbers for kelp get worse.
Kelp has vanished from about 80% of the shorelines around which it once grew in Puget Sound, according to a 2023 report from Washington’s Kelp Forest Monitoring Alliance. South of the Tacoma Narrows Bridge, the bull kelp beds are down some 90%. Around Bainbridge Island, they’ve all but disappeared entirely.
Like eelgrass, which cleans ocean water, absorbs greenhouse gases and supports a whole host of underwater species, bull kelp plays a crucial role within the Salish Sea. And in recent decades warming ocean temperatures, natural predators and human expansion have cut into kelp habitat. Entire ecosystems — from the microscopic to the grandiose — depend on the beds.
“Think of it as the old-growth forest under the ocean,” Woodard said.
At the moment, Woodard and others studying the decline of Puget Sound’s kelp beds can’t say for sure whether they’re stuck bearing witness to the downfall of an important aquatic species or if we’ll ever be able to build back what we’ve lost.
Bull kelp
Many different species of kelp exist across the oceans of the world but within Puget Sound’s subtidal zones, bull kelp reigns supreme.
As opposed to plants, kelp are classified as protists, said Jodie Toft, executive director of the Puget Sound Restoration Fund. They don’t have a traditional root system, just a series of anchors holding them to a single place like a rock or floor bed. And they photosynthesize (transform sunlight into food) and absorb nutrients all throughout their body.
Their stem (or stipe) is thick and somewhat firm, often thicker than the handle of a baseball bat, extending dozens of feet upward from the ocean floor. The species can grow as much as a foot in a single day. Their smooth but leathery blades flow in time with the motion of the saltwater.
Puget Sound’s underwater forests
Bull kelp (Nereocystis luetkeana) can grow as much as a foot a day. It uses air-filled bulbs to float in the water column, often forming large canopies. Other species of algae form middle and lower understory layers similar to terrestrial forests. This three-dimensional habitat provides refuge and food for a variety of marine animals, including shellfish, shrimp, juvenile rockfish and salmon. Adult salmon and killer whales patrol the perimeter looking for prey. Otters feast on urchins and kelp crabs, and cormorants perch on the canopy looking for their next meal.
Samish Department of Natural Resources, Puget Sound Restoration Fund, Abbott and Hollenberg 1976, Pfister et al. 2019, Springer et al. 2006 (Fiona Martin / The Seattle Times)
Kelp beds can grow to cover dozens of acres and they die off or retreat every fall, growing anew the following spring. Around them rise up microscopic organisms like algae, and larger creatures like kelp crabs and rockfish. The beds can be feeding grounds for otters and cormorants and serve as a refuge for salmon, tying kelp into the orca food chain.
They also hold a cultural and historical significance, Woodard said. The Samish people have used kelp as medicine and food, even fashioning the gas-filled bulbs to make toy rattles for their children. The beds are known as great fishing spots and because they calm rough seas, a good place for seafaring people to shelter during storms.
Kelp beds aren’t declining all over, some in the Strait of Juan de Fuca have been surprisingly resilient, Toft said. But they are falling fast across Central and South Puget Sound.
Why?
A convergence of threats
Perhaps the single largest threat to the kelp would be warming ocean waters, Toft said. While climate change is warming ocean waters consistently by several degrees, heat waves like “the Blob” in 2014 and 2015 can spike temperatures even higher, wreaking havoc on wildlife, in and out of the water.
are expected in the years and decades ahead.
Kelp grows best in cold waters, Toft said. Anything above a certain temperature (typically about 62 degrees Fahrenheit) and the kelp won’t grow nearly as well.
Think about incubating a chicken egg, said Megan Dethier, director of the University of Washington’s Friday Harbor Labs. Too hot and the early, microscopic stages of the kelp can die off or fail to properly develop. The egg will cook rather than grow a chicken.
But temperature isn’t the only factor, Dethier said. Some places with rising temps have kelp beds holding fast while some colder areas are seeing shrinking beds.
Predators also contribute, Toft said. On the California coast, the decline of sea otters have meant that urchins can overwhelm giant kelp beds, but that isn’t as much of a problem in Puget Sound. Rather, struggling rockfish numbers have meant that kelp crabs are more often left unchecked, which can eat away at the bull kelp beds.
Humans are also a problem, Toft said. Nutrient blooms from high levels of wastewater discharge or the over application of agricultural fertilizers can block sunlight from reaching the kelp deeper down.
Dethier is less sure that the increase of nutrients presents a problem for bull kelp. The species absorbs nutrients from the water and tends to thrive in high-nutrient areas, so long as the water churns enough to keep the area from going stale.
Humans also play a part in shaping the underwater landscape, Dethier said. Sprawling surface areas like streets, parking lots or car dealerships pour more sediments into the sound, which can bury the rocks and other hard surfaces kelp need to hold themselves in place.
“It doesn’t necessarily take a giant wad of sand,” Dethier said. “It can take a quarter-inch at the wrong time of year to kill the microscopic stage of the kelp.”
Tracking the decline of bull kelp across Puget Sound is undoubtedly a complicated and nuanced task, Dethier said. Additional research is needed to understand the problem and so we can consider possible solutions.
Samish Indian Nation
The kelp bed is easy to spot from a distance. The stipes look like a series of miniature logs floating on the surface, topped by bulbs about the size of a baseball.
The Samish kayak around the bed along the northwest coast of Burrows Island and another on the southwest point of Cypress Island, Woodard said. They dive at around six other beds to check on the overall health of the kelp and they track hundreds of beds across the entire San Juan archipelago with aerial photography.
Survey work for the kelp beds began in 2021, as part of a collection of state, local and tribal partners, Woodard said. Each partner plays a role in tracking the health of the kelp beds, surveying their area and investigating restoration strategies.
The group is gaining momentum too. In late August, the National Oceanic and Atmospheric Administration awarded the Samish Indian Nation and the nonprofit Friends of the San Juans nearly $500,000 as part of a regional climate resilience grant, tribal spokesperson Amanda Armstrong said.
Restoration work could take several forms, Woodard said. The tribe and the Puget Sound Restoration Fund are selecting several locations around the San Juan Islands where, next year, crews can try to plant kelp once more. They’re also keeping an eye out for certain subspecies of the kelp that seem to better withstand warmer waters, which could then be used to build beds back to their former glory, he said.
“We’re definitely out on the cutting edge of this,” Woodard said.
How effective will these restoration projects be, though, if the underlying problem of warming ocean waters doesn’t change? All signs point to the Earth warming even more in the decades ahead. The scientists aren’t too sure.
If they do nothing, conditions are all but sure to deteriorate further.
It’s a weighty topic, Woodard said. Think about it too long and the pessimism can creep in.
But, then again, you never know, he said. Every day, people come up with new and brilliant solutions to the world’s problems. Woodard said he’s bolstered by the nature of the partners across Washington, all looking to protect this critical underwater resource. He draws hope from the younger generations pouring themselves into the work, looking to make a brighter future for our planet.
