Fearing a threat to shellfish industry, Washington Legislature provides funds for kelp, eelgrass protection

SHELTON, Wash. – Bill Dewey walked through the Taylor Shellfish oyster FLUPSY – a floating upweller system used to grow shellfish in open water – in Oakland Bay on Tuesday afternoon.

He grabbed a shovel, pushed it into a floating box along the water and dug up hundreds of baby oysters, the edges of their shells paper thin. Once they are big enough, these will move to the oyster farm up the road where they will grow to the full-size, hard-shelled fish most people are familiar with.

Walking through the hatchery, there are thousands of baby oysters, just a portion of the 50 million sold by Taylor Shellfish every year. But not that long ago, it was a different story for Dewey, public affairs director at Taylor Shellfish.

In 2008, Dewey, a shellfish farmer himself, noticed his oyster seeds were dying, their shells disintegrating in the water.

After research from the National Oceanic and Atmospheric Administration, he found ocean acidification – when too much carbon dioxide gets into seawater making its pH less basic – was making it difficult for oysters to grow their shells, which they need for eating and moving.

Oyster farmers have since found ways to combat ocean acidification, but as climate change continues to heat the planet and more carbon dioxide makes its way into the water, many say it will get worse before it gets better.

One possible solution: growing kelp and eelgrass near oyster farms. The plants use the carbon dioxide in the water to their benefit, helping ease some of the ocean acidification.

“Eelgrass and kelp may be part of our saving grace down the road,” Dewey said.

The Washington Legislature this year provided the Department of Natural Resources with funding to create a plan to conserve or restore 10,000 acres of kelp and eelgrass habitats by 2040. By Dec. 1, 2023, the department must submit a plan to the Legislature for doing so.

As part of the department’s work to restore kelp and eelgrass, Commissioner of Public Lands Hilary Franz announced last month the state’s first Kelp and Eelgrass Protection Zone to conserve 2,300 acres of habitat near the mouth of the Snohomish River. It will prevent any development in the zone for the next 50 years.

The new funding and the protection zone follow the department announcing a new Watershed Resilience Action Plan, a 10-year blueprint to restore salmon habitat in the Snohomish River watershed.

In the past, Franz said the state’s approach to restoring salmon habitat has been an individual one. The watershed resiliency plan is the first time all the programs within DNR will work together in a comprehensive approach to address salmon habitat.

The plan will work similarly to the department’s long-term forest health plan, only the conservation will focus on the state’s underwater forests, Franz said.

“The state also has an unbelievable forest system that is underwater that is not so visible to the eye,” she said.

‘Drastic declines’ in kelp and eelgrass

South and Central Puget Sound have seen “really drastic” declines, said Cynthia Catton, science adviser at DNR. More recently, there have also been substantial declines farther north near the San Juan Islands.

According to research from DNR, the South Puget Sound has lost the majority of its bull kelp forests, declining 80% over the last 145 years.

“The threat to these habitats by climate change is recently feeling more tangible,” Catton said. “We are seeing more and more of our marine habitats undergo drastic shifts with really devastating impacts to our economies that rely on them.”

Its research found some possible stressors causing the loss of kelp include warming climate conditions, kelp crab grazing, water quality degradation, trophic changes and decreased spore availability.

In creating its watershed resiliency plan to restore kelp and eelgrass, DNR will begin by looking closer at what those stressors are and what they can do to restore it.

DNR’s main focus in preserving kelp and eelgrass is improving salmon habitat.

Franz said salmon are losing critical habitat when kelp forests decline. It’s often where the fish forage, lay eggs and hide from predators. Salmon, especially young salmon, use kelp and eelgrass forests to move through the ocean.

Improving kelp and eelgrass could change the trajectory that salmon are on, Franz said.

But these underwater forests are home to a number of other species of fish, invertebrates and mammals, including orca, Catton said.

“If we lose our kelp forest, then we lose everything else that relies on it,” Catton said.

Kelp and eelgrass also have benefits outside of the habitat they provide.

Ocean acidification

Ocean acidification is caused when too much carbon dioxide, produced when humans drive cars or pour cement for example, gets into the water. When there is too much carbon dioxide, it causes a reaction that makes the ocean less basic.

It can have harmful effects on animals and plants in the water, especially those, like oysters, that have parts made of calcium carbonate, or a chalklike substance.

It was first noticed in Washington when the shellfish industry started seeing their oyster seeds dying, said Meg Chadsey, an ocean acidification specialist at Washington Sea Grant at the University of Washington.

When oysters are about two days old, they have to convert about 80% of their body weight into a shell. They get the building blocks for that shell from sea water, Chadsey said. They can’t feed themselves or move until they have that shell.

Beginning in the early 2000s, the acidity of the water reached a point where oyster shells were dissolving more easily, Chadsey said.

From 2008 -09, Dewey said the industry was in a “seed crisis,” having lost 75% of what they normally had.

The impact of ocean acidification on the shellfish industry was one of the first examples of climate change affecting Washington’s local economy, Catton said.

The shellfish industry has learned to adapt to the ocean acidification by testing and treating the water at hatcheries, Dewey said. But the problem will likely get worse before it gets better.

Many people might think the problem’s fixed because the shellfish industry has learned to adapt, Dewey said, but “they’re just not looking that closely.”

“While we can fix the problem in hatcheries, we can’t fix the problem in the whole ocean,” Chadsey said.

The water that caused the problems in 2008 was actually 30 to 50 years old, coming up from the very bottom of the ocean, Dewey said. That means there will likely be more water cycling over the next 30 to 50 years that is just as problematic, if not more.

‘Still a long way to go’

One solution is growing oysters next to kelp and eelgrass forests.

Just like plants on land, kelp and eelgrass can take the carbon dioxide in the water and turn it into a solid. If these plants use up much of the carbon dioxide in the water, the acidification might not be as bad, Chadsey said.

Dewey has started using some kelp and eelgrass in some of his farms. He said kelp and eelgrass can be “potential refuges” for their oysters.

Protecting the natural kelp and eelgrass, like the Department of Natural Resources is trying to do, could also help with this problem, Chadsey said.

“You can’t cure the ocean of acidification, but you can do local mitigation,” she said.

The shellfish and other marine industries will have to continue adapting to ocean acidification, Dewey said.

While the kelp and eelgrass funding is a good start, there is still a long way to go to address ocean acidification and climate change, Chadsey said.

“Seagrass and kelp aren’t going to solve the problem by themselves,” Chadsey said. “But there’s lots of things we can do, and if we do most of them at the same time soon, we stand a good chance at turning this ship around.”