According to professor Charles Yarish, shellfish and seaweeds can provide good ecosystem services (Photo:Peter Morenus, uconn.edu)
Seaweed could be used to clean up polluted waters
Thursday, January 06, 2011, 02:20 (GMT + 9)
Stanford professor of ecology and evolutionary biology Charles Yarish is working to use seaweeds to clean up pollution and waste from farmed fish and even humans. Called extractive aquaculture or bioextraction, the process will employ the physiological properties of seaweeds and other organisms to remove excess nutrients from polluted areas.
“Nutrient-enriched systems can contribute to harmful algal blooms, which deplete oxygen in the water,” elaborated Yarish. “Shellfish and seaweeds can provide good ecosystem services by extracting organic and inorganic nutrients from seawater.”
Last year, Yarish and his team received almost USD 200,000 from the Connecticut Sea Grant College Programme and the National Oceanic and Atmospheric Administration’s (NOAA) Small Business Innovation Fund to grow seaweeds for human consumption and to create technologies that will sustain IMTA in New England, reports the University of Connecticut.
Fish waste and nutrients derived from sewage treatment facilities and from land runoff all provide inorganic nutrients such as nitrogen and phosphorous, which various types of seaweed need to survive.
Last February, Yarish and Chris Neefus of the University of New Hampshire established a seaweed culture in his laboratory to be used as a “seed bank” to grow the seaweeds on fish farms.
|Yarish, who has studied seaweeds for many years, now hopes to use them to clean up water pollution. (Photo:Peter Morenus, uconn.edu)
The researchers also worked with students and faculty at the Bridgeport Regional Aquaculture Science and Technology Education Centre to develop an open-source online resource explaining the specific methods for cultivating seaweeds in aquaculture. The techniques have been used by NGO Ocean Approved, a sea vegetable firm from Maine that is collaborating with Yarish and graduate student Sarah Redmond to grow edible kelp.
Yarish and Ocean Approved are working on a kelp culture that grows on ropes suspended in the water column and linked to floats or raft systems from the company’s mussel farm. Ocean is selling this all-natural kelp in New England.
“It’s a high-value, good-tasting, biosecure product,” said Yarish.
And as part of a USD 2.4 million initiative funded by the Long Island Sound Futures Fund, he is working to found and support conservation projects in the region.
The Long Island Sound’s waters are consistently high in nutrients from waste water treatment plants and land runoff. The East River is particularly polluted.
|One of Yarish's projects teams seaweed with filter feeders, such as clams and mussels, for purposes of bioremediation. (Photo: Peter Morenus, uconn.edu)
Because seaweeds clean up inorganic nutrients from water and clams, mussels and their ilk filter organically bound particles rich in nutrients, the combination of these two organisms could work powerfully, noted Yarish.
He and his team are growing seedstock of a native red seaweed, Gracilaria, for use in the East River. They will be transferred to the Bridgeport Regional Aquaculture Science and Technology Education Centre to grow until large enough to be taken to its open water research farm in western Long Island Sound and the East River.
Yarish hopes to employ Gracilaria near the confluence of the Bronx River and the East River from late spring through the fall so coastal managers can model the bioextraction services of the seaweed and ribbed mussels. If successful, it could be applied anywhere.
Yarish is also working on IMTA systems used to farm fish for commercial purposes and whose waste products can pollute surrounding waters.
By Natalia Real