| *Another
important concept is Eutrophication and there are two kinds: |
|
| *Natural
eutrophication is the process by which lakes gradually age and build up
nutrients which normally takes thousands of years to progress. However, humans have greatly accelerated this process through our various cultural activities and this is called cultural or anthropogenic eutrophication. *Humans add excessive amounts of plant nutrients (primarily phosphorus and nitrogen) to streams and lakes in various ways. |
|
| *Some examples
of sources include Runoff from agricultural fields, field lots, urban lawns,
and golf courses. |
|
| *Untreated, or
partially-treated, domestic sewage is another major source. Sewage was a
particular source of phosphorus to lakes when detergents contained large
amounts of phosphates. The phosphates acted as water softeners to improve
cleaning, but they also proved to be powerful stimulants to algal growth
when they were washed or flushed into lakes. |
|
| *diagram |
|