What Are the Water Quality Trends of
Lake Martin?
*For year-to-year comparisons, all chlorophyll a values were |
The graph above represents research results of ADEM and Auburn University, and plots the changes in Lake Martin TSIs at both a lower lake site (blue line, Dam Forebay) and an upper lake site (green line, Highway 280 bridge crossing) over a ten-year period (see map). Dots represent the average TSI for the growing season (April through September, 1 - 6 readings per growing season).
At the lower lake site, the trophic state of the lake has changed from upper-level oligotrophic to lower-level mesotrophic. This present condition probably characterizes much of Lake Martin and explains why the lake is still relatively clear and so attractive for fishing, swimming and other types of water recreation.
The upper lake site is quite different from the lower site, however, and has changed from mid-level mesotrophic to eutrophic during this same period. The rate of increase in TSI is also somewhat greater than at the lower site.
In summary, research information indicates that Lake Martin is undergoing changes due to human activity that results in increased polluted runoff from Alexander City and other parts of the watershed. Nutrients from lakefront lawn and garden fertilizers and faulty septic systems are also contributing to this "eutrophication" process. These changes are most obvious in the upper lake (closer to the main sources of pollution) and are gradually affecting the entire lake.
It is important that the public and policy makers are aware of these trends, and that they collectively work toward protecting Lake Martin from further degradation. There is no such thing as a single trophic state that is "optimal" for all lakes, however. Ideally, each lake should be protected and managed according to the objectives of all stakeholders, including watershed residents and governmental agencies.
This report was compiled by Alabama Water Watch program personnel
in partnership with Lake Watch of Lake Martin.
