Wetland ‘islands’ launched in Cullaby Lake to deter algae

Two manmade islands, designed to combat a blue-green algae problem, are floating on Cullaby Lake. The Skipanon Watershed Council, in partnership with the North Coast Watershed Association, joined the community to plant a second floating wetland island at Cullaby Lake County Park near Gearhart earlier this month…

The newest “island,” dubbed “Big Coho,” is part of a treatment used around the world that mimics the positive effects of a concentrated wetland to confront nutrient pollution.


“Big Coho” is the second of its kind at the Clatsop County lake. Last year, Gail Galen, who owns several acres on Cullaby Lake, had the idea to “clean” the water using native plants to reduce nitrogen and phosphates.

She got the idea from a New York Times article about floating wetland islands being used in Mississippi. The article said about 4,800 of them have been installed around the world. Galen sent away for one from Floating Islands West, LLC, the West Coast manufacturer and distribution center for BioHaven Floating Islands.

“The whole idea of remedying something naturally just really appealed to me,” she said.

She personally planted a similar island that, by default, is called “Little Coho.” That was after the blue-green algae problem at Cullaby Lake had become so severe that Oregon Health Authority’s Public Health Division and Clatsop County Health Department officials issued an advisory and closed the lake for several months in 2011.

In June 2011, Cullaby Lake was included on the Oregon Department of Environmental Quality’s bodies of water where potential algae blooms could be of concern. DEQ noted specifically a few varieties of blue-green algae, including aphanizomenon flos-aquae and anabaena spiroides.

Cullaby Lake also has been included on DEQ’s most recent list of impaired waters in Oregon. The list was compiled in December 2012 after review by the federal Environmental Protection Agency. DEQ is required to assess the quality of its water bodies every two years in compliance with the Clean Water Act.

According to the Oregon Health Authority, not all blue-green algae produce toxins and when produced, the toxins are not always at harmful levels.

Algae expert Wayne Carmichael, who attended the planting event to answer questions from participants about the blue-green algae, said in an interview that the algae so far dominant in Cullaby Lake are the correct genus but not the right species to produce toxins.

However, in the long term, his concern is that if the nutrients are not controlled and reduced, they will propagate the type of algae that can produce toxins.

Exposure to the toxins can have detrimental effects, particularly to children and pets. Symptoms may include numbness, tingling, dizziness, skin irritation, weakness, diarrhea, nausea, cramps and fainting.

More broadly, the blue-green algae negatively affects the lake’s aesthetics, and homeowners, like Galen, are worried it will depress property values.

Galen said she has not seen an instance of the blue-green algae yet this year.

Carmichael, who is on the boards of both the Clatsop County Soil and Water Conservation District and Oregon Lakes Association, said the appearance of the algae depends on several factors, including weather. The algae can come and go but, in general, things seem to be getting worse, he said.

About four months ago, the Skipanon Watershed Council approved a motion to partially refund Galen for Little Coho and fully fund Big Coho. The island cost about $2,000, including $1,610 for the actual island and $365 for shipping.

The main characters in the floating wetland treatment being used at Cullaby Lake are scirpus validus, or soft-stemmed bulrush; carex obnupta, or green slough sedge; juncus patens, spreading rush; and Rosaceae spirea.

The floating islands are made from recycled material and designed to imitate the effect of wetlands. As they grow, the native plants absorb nutrients like nitrogen and phosphates.

At the event May 4, a small group of participants sowed 140 plant plugs using three of those varieties onto Big Coho before launching it out on the lake. As they grow, the plants, which are native to the area, are meant to help mitigate the algae by taking nutrients out of the water and producing shade to prevent the algae from thriving, Carmichael said.

The islands themselves are made from recycled plastic bottles that also support the biological process to reduce the nitrogen and phosphates.

Carmichael said the floating islands do what they’re supposed to do, but they’re not going to impact the problem significantly.

“I think it’s a good idea, it’s a step in the right direction. … The Skipanon Watershed Council is to be commended for at least trying something and taking one small step in the right direction,” he said, adding that some kind of nutrient control would be necessary to make a larger stride.

Galen agreed she would like to discover the nutrients’ sources.

“It seems to me it would make sense to have a string of these islands stationed at these positions” where nutrients are being produced, she said.

Galen is attempting to obtain three-year permits for the islands from Oregon’s Department of State Lands. She hopes that the islands will be “ambassadors for water quality” by raising public awareness and also become resources for experiments, education and assessment.

For instance, John Rueter, professor of environmental science and management at Portland State University, has expressed interest in using the islands to conduct a wind study on the lake from July to December this year, Galen said.

“My dream would be, if we got some students involved, this would be a teaching opportunity,” she added about the floating wetland treatment.

Carmichael said the Oregon Lakes Association’s annual meeting — to be held in Astoria in October — will have the theme “Lakes of Clatsop Plains: Past, Present and Future” and focus on topics directly relevant to nutrient pollution and cleanup in Cullaby Lake.

Photo caption: A second floating wetland island, Big Coho, was planted in Cullaby Lake by the Skipanon Watershed Council earlier this month. Big Coho and its counterpart, Little Coho, which was planted last summer, are part of a pilot project aimed at reducing blue-green algae in the lake.

Seaside Signal, Daily Astorian

View original article at: Wetland ‘islands’ launched in Cullaby Lake to deter algae

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