Sea lettuce stirs up a stench


The Mirror

In the past five years, some residents on the shoreline of Dumas Bay have noticed a stench, similar to sewage, hanging in the air come summertime.

The city has gotten about half a dozen complaints about the smell, said Paul Bucich, Federal Way surface water manager. Most of the complaints came this past summer. When residents began noticing the stench, several thought it came from the Lakehaven Treatment Center, he said.

However, Lakehaven Utility District evaluated the center and determined it was not the cause, which left residents and city officials alike wondering where to find the smell’s source.

Further research determined it is caused by ulvoids, which are naturally occurring forms of seaweed also referred to as sea lettuce. As the temperature climbs and the sea lettuce begins to decay, the smell worsens.

The wind then carries the stench along the shoreline, across Southwest Dash Point Road and into residential neighborhoods, Bucich said. For many people it did not seem possible that such a smell could be produced by seaweed, Bucich said.

“It’s a big stench and a big source,” he said.

The city has deemed the sea lettuce a problem, and has determined that it ought to be removed, Bucich said.

However, most of the details that accompany that decision leave city officials stumped, he said. The city does know that the nutrient levels in Puget Sound need to be addressed or the sea lettuce will likely return.

The city’s official stance on the Dumas Bay stench: It will not lead the efforts in removing the sea lettuce, but is willing to call together and work with the necessary organizations to do so, Bucich said.

The sea lettuce in Dumas Bay stretches along the shore for more than half a mile and into the water for an unknown distance, said Dan Smith, Federal Way surface water quality program coordinator.

Sea lettuce feeds off sunlight and nutrients, such as fertilizers, that make their way into Puget Sound, Bucich said. The sea lettuce continues growing in layers, requiring more oxygen as it does, he said.

Layers that do not receive adequate oxygen begin decomposing. When the layers are torn apart by waves, animals or humans, they release hydrogen sulfide, a potentially dangerous gas when encountered in high levels, Bucich said.

The gas is what residents in the area are smelling, he said.

The sea lettuce serves as food for sea creatures, and in small amounts, it does not pose any significant danger to animals or humans, said Dave McBride, a Washington State Department of Health toxicologist. Eye, throat and lung irritation as well as some nausea, coughing, headaches, fatigue or loss of sleep may occur at low levels, he said.

People have a wide range of tolerance to the gas, so determining how each person in the Dumas Bay area will be affected is difficult, Smith said. Those already suffering from asthma or respiratory problems will probably be more prone to its effects, he said.

Removing the problem

Although McBride does not foresee a potential health concern for most residents in the area, the city would still like to see the sea lettuce removed, Bucich said. Not only have residents complained about the smell, but as it spreads, the sea lettuce deprives other plants and animals of oxygen. Eel grass, crabs, sand dollars and other wildlife could be affected, Bucich said.

Throughout Puget Sound waters, nutrient levels are increasing, which may be one reason the growth of the sea lettuce has become more noticeable in multiple areas, Bucich said. The problem is bigger than Dumas Bay and must be addressed as a whole, he said.

“Puget Sound is changing,” Smith said. “It can’t handle the (nutrient) input.”

Federal Way has taken the initiative to call together representatives from the city, Puget Sound Clean Air Agency, Washington State Department of Health, Washington State Department of Ecology, Washington State Department of Natural Resources and the Washington State Department of Fish and Wildlife. However, it seems the sea lettuce and its smell do not easily fit any of the city or state departments’ required criteria for mitigation.

Although the stench is distributed in the air, it is produced by natural occurring growth, not humans. Therefore, the Puget Sound Clean Air Agency is not responsible for removing the smell.

Federal Way does not have the resources or know-how to successfully and safely remove the sea lettuce, Bucich said. Also, the property along the bay is privately owned, so residents would have to approve the removal, Bucich said.

If one resident did not approve, the sea lettuce could keep growing and spreading. Even if the city altered its stance on the project and decided to lead the removal efforts, it is still likely the sea lettuce could return.

“It’s like pulling weeds out,” Smith said. “It looks good for a while, but they come back.”

In addition, the process must be done in a way that does not threaten wildlife or residents, Bucich said.

Also, disposing of the growth would pose another problem. The cost per ton to remove sea lettuce would be $40. The sea lettuce would have to be dry, so as to decrease smell and costs, before it was hauled away from the beach, Bucich said.

The smell is one that must be addressed by the Washington State Department of Ecology, Bucich said. The department has the resources to research the sea lettuce and determine its severity as well as remove it, he said.

The state Legislature recently allocated $300,000 to the Department of Ecology with orders to address a similar problem that has been in effect in West Seattle’s Fauntleroy Cove since 1980.

Federal Way had requested to receive a portion of that money. However, the city learned May 22 that the Legislature denied that request.

The city would like to see the Department of Ecology take on and lead the sea lettuce removal efforts, Bucich said.

A letter was submitted by City Manager Neal Beets to the Department of Ecology on March 6, asking the department to find funding in its current budget to lead efforts in removing sea lettuce in Dumas Bay.

The city has not gotten a response from the Department of Ecology, Bucich said, and is not sure what will happen if the department does not respond, he said.

This leaves the city with a stinky problem and no concrete idea of how to resolve it.

“We’re in limbo,” Bucich said.

Contact Jacinda Howard: or (253) 925-5565.

Learn more

To learn more about the sea lettuce in Dumas Bay, call (253) 835-2700.


The May 26 Federal Way Mirror article titled "Sea lettuce stirs up a stench" said the City of Federal Way had not received a response to a letter sent March 6, 2007, by City Manager Neal Beets to the Washington State Department of Ecology asking the department to lead efforts in removing sea lettuce in Dumas Bay.

On May 25, Paul Bucich, Federal Way surface water manager, received a letter dated April 11, 2007, from the Washington State Department of Ecology.

The letter detailed that the Department of Ecology knew of the sea lettuce problem in Dumas Bay as well as that in West Seattle's Fauntleroy Cove. However, the department felt there was not enough sea lettuce in the Dumas Bay area to cause health concerns.

The Department of Ecology noted that Joe's Creek, which drains into Dumas Bay, is an impaired body of water that may be contributing to the sea lettuce growth in the bay. The department offered to investigate and improve the water quality in Joe's Creek, but refused to lead efforts in removing the sea lettuce.

Instead, the Department of Ecology suggested Federal Way form a task force of local, state and federal authorities to confront the problem.

"Because seaweed odor is a widespread problem on many beaches throughout the Puget Sound area, there is also the question of the adequacy and reasonableness of the use of state funding for the purpose of addressing local site problems," wrote Jay Manning, Washington State Department of Ecology director.

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