If the weather during the rest of the summer remains hot and calm, this year may well be remembered as one of the worst for blue-green algae bloom in recent memory on Lake Champlain. That is too bad, because it means days of ruined beach visits, vacations when kids can’t go in the water and declines in income for lakeside businesses. But it could also cause a shift in attitude about what lake phosphorus pollution means, and how serious we are about dealing with it. And that would be a good result from a bad situation.
One of the interesting things about blue-green algae, or cyanobacteria as they are more accurately known, is that, unlike an invasive species or pollution by hazardous materials, they are normal inhabitants of land and water – and are nearly ubiquitous in some places. They become a problem, and a major one, when we cause the ecosystem to be out of balance. Otherwise, we would rarely think about them.
How do blue-geen algae become a problem? Under certain conditions, cyanobacteria explode into massive blooms. During the early stages of such a bloom, they look like pollen in the water and are easy to ignore. But as their volume increases, the blue-green algae can become a thick, paint-like mass that stacks up into white, blue and green froths, choking waterways, blocking sunlight, and, when they decompose, reducing the amount of oxygen in the water to dangerously low levels. Those conditions cause massive die-offs of fish and shellfish – and stinking piles of rotting algae along the shoreline.
Beyond all these problems, in such large volumes the cyanobacteria at times produce toxins which can sicken people and kill pets. In the late 1990s and early 2000s, before people were familiar with the dangers of cyanobacteria blooms, dogs died from ingesting those toxins. In other parts of the country, people have become very sick as well, including U.S. Senate Environment and Public Works Committee ranking member James Inhofe, who became ill in 2011 after he went swimming back in his district in Oklahoma. Inhofe, well-known for his opposition to much anti-pollution legislation, joked that the news story about his experience should bear the headline “the environment strikes back.”
So far this year, few blooms on Lake Champlain have reached the dense stage of development where they test positive for cyanotoxins. But parts of the lake that do not often have such blooms are now seeing cyanobacteria. Last year’s flooding from tropical storm Irene dumped record loads of phosphorus into Lake Champlain tributaries, providing the nutrients needed for blue-green algae populations to explode. And this dry, hot, calm summer has provided the right conditions for that population explosion to happen.
If people from those lake areas that are experiencing unprecedented blue-green blooms get together with those from other places – like St. Albans Bay and Missisquoi Bay where such blooms are almost yearly occurrences – we may be able to chart a different path and keep such problems from spreading any further.
With better farm management techniques, improved urban runoff systems and up-to-date sewage plants, we can prevent the otherwise inevitable spread of cyanobacteria to more places on Lake Champlain. If we can make that happen, this summer might go down in the books as not just the worst blue-green summer, but the summer in which things began to change for the better.