This chart created by the Addison Independent from Vermont Agency of Natural Resources, Water Management Division data shows the number of metric tons of Phosphorus in Lake Champlain per year from 1991 through 2011. The chart focuses on three Vermont watersheds, namely Otter Creek, the Winooski River and the Missisquoi River.
Last year’s record spring flooding and Tropical Storm Irene caused unprecedented amounts of phosphorus to be dumped into Lake Champlain. In some cases the amounts were two to three times the average high mean levels. These high Phosphorus levels are responsible for the widespread and sudden appearance of Blue-Green Algae, or cyanobacteria blooms that have closed beaches around the Lake.
“Phosphorus is key to causing the dense cyanobacteria blooms,” according to Angela Shambaugh, aquatic biologist for the Water Management Division at the Vermont Agency of Natural Resources and a leading authority on cyanobacteria. “That bulk of algae really can’t grow without phosphorus, and it takes a lot of phosphorus to create that amount of biomass.”
In Vermont, cyanobacteria live in warm, shallow waters that get lots of sun and low winds. And they flourish most where their primary source of food – phosphorus – is most abundant. As the above chart illustrates, Lake Champlain Phosphorus levels have never been higher. Warmer weather and calmer wind and waves provide the ideal conditions for the formation of Blue-Green Algae blooms and have contributed to our current outbreaks.
Boaters, swimmers, water-skiers, waders, parents, pet-owners and residents should become familiar with the appearance of blue-green algae (cyanobacteria). Avoid contact with dense accumulations of these algae. Children are at higher risk because they are more likely to drink the water. Pets should not be allowed in algae-contaminated water, because they will also drink the water and consume algae on their fur.
For more information on the causes, dangers and prevention of Blue-Green Algae blooms see Blue-Green Algae Tips.
Blue-Green Algae Tips, (LakeChamplainLife.com)
Lake Champlain Blue-Green Algae Bloom Status Map, (Vt Dept. of Health)
Lake Champlain, Environmental Reports, (VT ANR)
Blue-green Algae, Information Bulletin, (NYS Dept. of Health)
Blue-green algae and our surface water, (MDDEP, Quebec)