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Nutrient release from anoxic sediments

?where should this go? !hypoxia (environmental) and link to these:


Anoxic sediments can release phosphorus, a limiting nutrient, into the water column. This can lead to an increase in algae population, or even an algal bloom. In the absence of oxygen from the sediments, benthic microbes WHAT TYPES??? turn to other substances to reduce for respiration(?) [1]. These include iron and sulphur.

The iron in the sediments is often in the form of FeIII OOH ( iron(III) oxide-hydroxide or iron(III) hydroxy oxide or ferrihydrite), which when reduced goes to FeII. FeOOH is a good chelating agent that adsorbs much of the phosporus in the sediments, however, FeII doesn't, so the phosphorus is released WHAT FORM?.

The reduction of sulphur compounds by microbes WHICH TYPES? produces SO2 sulphur dioxide gas, known for it's smell of rotting eggs (rotten egg gas) [2].


..as the surface of the sediments turn anoxic when the water column has?? a bit dodgy..then: is it when there is low DO or must it be anoxic?

Phosphorus is the limiting nutrient in Australian/ or all?? water systems, esp freshwater [1]? and the majority is tied up in the sediments. Thus, phosphorus releases can promote algal blooms. Severe algal blooms can promote anoxia, and so perpetuate the cycle of algal growth, and destabilise macrophyte dominated systems.



See also: p-cycle

Related topics

References

  1. ^ a b Boulton and Brock, Australian freshwater ecology: processes and management. Gleneagles Publishing, Mt Osmond, South Australia, 1999.
  2. ^ Wetzel. Limnology:Lake and River Ecosystems 3rd Ed. 2001?