Main Effects Of Eutrophication

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Eutrophication
On
River Ecosystem

Eutrophication Excessive richness of nutrients in a lake or other body of water, frequently due to run-off from the land, which causes a dense growth of plant life. Eutrophication arises from the oversupply of nutrients, which induces explosive growth of plants and algae which, when such organisms die, they consume the oxygen in the body of water, thereby creating the state of hypoxia (deficiency in the amount of oxygen reaching the tissues)

Mechanism of Eutrophication
When algae die, they decompose and the nutrients contained in that organic matter are converted into inorganic form by microorganisms. This decomposition process consumes oxygen, which reduces the concentration of dissolved oxygen. The depleted oxygen levels in turn may lead to fish kills and a range of other effects reducing biodiversity. Nutrients may become concentrated in an anoxic zone and may only be made available again during autumn turn-over or in conditions of turbulent flow.
Enhanced growth of aquatic vegetation or phytoplankton and algal blooms …show more content…

Species diversity decreases and the dominant biota changes
2. Plant and animal biomass increase
3. Turbidity increases
4. Rate of sedimentation increases, shortening the lifespan of the lake
5. Anoxic conditions may develop

Ecological Effects
Many ecological effects can arise from stimulating primary production, but there are three particularly troubling ecological impacts: decreased biodiversity, changes in species composition and dominance, and toxicity effects.
• Increased biomass of phytoplankton
• Toxic or inedible phytoplankton species
• Increases in blooms of gelatinous zooplankton
• Increased biomass of benthic and epiphytic algae
• Changes in macrophyte species composition and biomass
• Decreases in water transparency (increased turbidity)
• Colour, smell, and water treatment problems
• Dissolved oxygen

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