Seaweeds can detoxify organic pollutants
18 March 2005, CIESM News

Researchers have discovered that marine seaweeds have a remarkable and previously unknown capacity to detoxify serious organic pollutants such as TNT or polycyclic aromatic hydrocarbons, and they may therefore be able to play an important role in protecting the ecological health of marine life. The findings may have important implications for seafood safety, since some of the marine organisms most at risk from these toxins are marine invertebrates such as clams, shrimps, oysters or crabs that tend to “bioaccumulate” them. One possibility, the researchers say, might be to plant appropriate seaweeds as a protective buffer around areas being used in aquaculture.

They found that certain red seaweeds had an intrinsic ability to detoxify TNT that was 5-10 times faster than any known terrestrial plant. The researchers call this process “phycoremediation”, derived from ‘phykos’, a Greek word for seaweed. The studies are particularly important in the case of TNT, because of unexploded bombs or military shells found in some places around the world’s oceans. There is concern that these shells could potentially corrode. The study is also looking at polycyclic aromatic hydrocarbons, such as naphthalene, benzopyrene and other PAH’s that are sometimes associated with the use of ships.

Researchers found that marine seaweeds processed toxins to a much less harmful form, and did not appear to harm the seaweed. The biochemistry involved is similar to that found in many land organisms, but more powerful and effective. The capability of marine seaweeds to deal with these toxins has never been demonstrated until now. These research outcomes should lead to the development of new bioremediation technologies that use seaweeds in engineered systems to remove organic contaminants from the marine environment. Studies to create genetically engineered seaweeds that perform these functions even better also look promising.