What's Polluting our Rivers, Lakes, and Estuaries I: Phosphorus
First Paragraph:
Phosphorus is a naturally occurring element that is
essential for all plant and animal life, and is found in
some amount in all natural ecosystems. It is necessary
for critical functions in living cells and is found in
the bones and teeth of many vertebrate animals. It is
found in plant debris, animal wastes, and bound to
soil particles. Because it is so common, some loading
of phosphorus to waterbodies is natural, but human
activities may increase this amount. In natural systems,
phosphorus is often found in relatively low quantities
in the soil. Because of this, fertilizers containing
phosphorus are often added to lawns, gardens, and
agricultural fields to promote optimum plant growth.