A recently released national assessment of the nation’s lakes has found that 4 in 10 lakes have too much nitrogen and phosphorus.
Excess nutrients can cause algae blooms, lower oxygen levels, degrade habitat for fish and other life, and lower water quality for recreation. The National Lakes Assessment also found an algal toxin – microcystin – in 39% of lakes, but below levels of concern. Low concentrations of the herbicide atrazine were found in 30% of lakes. Read more