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Other experimental solutions

In stratified eutrophic lakes there is lack of oxygen. This anaerobic condition at the sediment surface result in the release of phosphate that becomes available to algae for photosynthesis and production of more organic matter. This cycle can be broken by aeration: the injection of air at the bottom of lakes prevents thermal stratification and hence deterioration in water quality.

An alternative, generally more expensive technique is to remove the sediment entirely, thus both taking away the internal source of phosphorous and deepening the lake.

Other technique experimented in the past to prevent the recycling of nutrients or to accelerate the outflow of nutrients have included sealing lake bottoms with polyethylene sheeting, selectively discharging hypolimnetic water in water supply reservoirs, or diluting with water from an oligotrophic source.

Through laboratory and field experiments it was proved that moistened clay weighs down algal cells, causing them to sink [7]. Algae stick to clay particles just as a magnet clings to iron. When clay is sprayed onto the surface of waters contaminated with harmful algae, the algal cells attach to the clay, become burdened with its heavy load, and fall to the seafloor. On the way down, the algae-clay particles collide with and gather more algae, forming masses of fluffy debris called marine snow. In the United States, clay treatment is not yet permitted as a control strategy for algal blooms because there are questions about the ecological consequences of this sort of remediation. Further research is being carried out to find out how this falling debris affect the organisms on the seafloor.

Related topics

For more books and reading information see our website:
Eutrophication books overview

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