Re: What is the effect of low levels of Phosphoruse on an aquatic ecosystem???

James:

In many ecosystems phosphorus is a limiting nutrient. This means that as 
the bodies of organisms are searching for nutrients in the environment, 
phosphorus is commonly the first nutrient to become scarce or unavailable. 
The result is that organisms are less numerous and/or smaller than they 
would be if phosphorus was more abundant.

Phosphorus is a critical nutrient -- organisms have to have it. It plays a 
role in photosynthesis in plants, and is important in energy transfer 
within organisms. DNA includes phosphorus so all organisms need it for 
growth and reproduction. 

If animals don't have enough phosphorus, rickets (improper bone 
calcification) is one consequence. In plants, a lack of phosphorus arrests 
growth, delays maturity, and stunts roots. 

I hope this helps. If you have any further questions, please do not 
hesitate to ask.

David C. Kopaska-Merkel
Head, Ground Water Section
Geological Survey of alabama
PO Box 869999
Tuscaloosa AL 35486-6999
(205) 349-2852
FAX (205) 349-2861

Reference:

R. L. Smith, 1974, Ecology and field biology, 2nd ed., New York, Harper and 
Row, 850 p.