Quality: Management, Sanitation and Investigation
is a term used to describe the aging of a lake. This aging process
results from the accumulation of nutrients, sediments, silt, and organic
matter in the lake from the surrounding watershed.
be accelerated when human activity occurs in the watershed. If proper controls
are not in place, pollutants from agricultural, urban, and residential
developments can easily be carried into lakes and their tributaries.
Symptoms of human-induced
cultural) eutrophication are:
These conditions are
usually considered symptomatic of cultural eutrophication.
increased algal growth
(stimulated by increased supply of nutrients);
increased rooted aquatic
plant growth (stimulated by the increased supply of nutrients as well as
the creation of additional shallow growing areas via the accumulation of
sediments, silt and organic matter); and
lower dissolved oxygen
concentrations in all or parts of the lake (as a result of increased plant
respiration and the decomposition of organic matter by bacteria and other
microorganisms. This lack of oxygen can kill fish and other aquatic life).
each condition nevertheless has a unique set of parameters that characterize
its attributes. It is important to remember that sampling for one condition
will not necessarily yield information about another. If, for example,
a lake has an aquatic plant problem, a monitoring program that focuses
on algae will not provide the necessary answers to solve that problem.
The reader should
be aware that there are several other lake conditions that could be a potential
focus for a management, monotoring and restoration program. Four notable
Each of these conditions
has the potential to severely affect the water quality and recreational
use of a lake or reservoir.
sedimentation on the
lake bottom (reduction of water depth);
sediment turbidity (reduction
of water clarity as a result of suspended sediment);
of bathing beaches.