As the days lengthen and the air warms, sun worshippers are soaking up the rays. On land, the grass is lengthening, trees are greening, and mammals of all kinds are shedding their winter coats. In water, algae are also responding to the increasing sunlight. These tiny organisms, often not visible to the naked eye, are present in all waters and are a crucial component of aquatic food webs.
The generic term ‘algae’ is used for all microscopic aquatic organisms capable of photosynthesis. Freshwater algae are a very diverse group. Lake Champlain alone has more than 150 species. Like plants on land, different species are abundant at different times of the year. In spring and early summer, diatoms, like those shown in the photo, are most common. Later on, green algae and cyanobacteria (also called blue-green algae) are predominant. Many freshwater algae are quite beautiful when viewed with a microscope. Check out the photo gallery of Great Lakes algae on the National Oceanic and Atmospheric Administration (NOAA)’s Great Lakes Environmental Research Laboratory website. Many of these are found in Lake Champlain as well.
Most of us rarely notice algae until they form visible mats or change the color of the water as they become very abundant. Excessive algal growth is a nuisance and, in some cases, poses a health risk for people or animals because of the toxins the algae may produce. In Vermont, toxins produced by cyanobacteria have been found in parts of Lake Champlain and other smaller inland lakes. In recent years, more than 90% of the observations from Lake Champlain documented good conditions with respect to algae, but there are times when cyanobacteria growth is excessive. Because of this, it’s important that everyone learn to recognize situations when it’s prudent to avoid contact with algae.
For over a decade, researchers at the University of Vermont, staff from the Vermont Departments of Health and Environmental Conservation, and citizen volunteers organized by the Lake Champlain Committee (LCC) monitored for cyanobacteria and the cyanotoxin microcystin on Lake Champlain. The data were used to develop a protocol for assessing cyanobacteria conditions and the possibility of illness after exposure. Now, a group of dedicated LCC volunteers and state field staff collect data on cyanobacteria each summer from locations around Champlain. Results are shared with the public through an interactive webpage hosted by the Vermont Department of Health – http://healthvermont.gov/enviro/bg_algae/weekly_status.aspx – so that everyone can be aware of lake conditions.
Before you head out to play this summer, take the time to learn about cyanobacteria. Once you recognize what they look like, Vermont offers hundreds of places to safely enjoy the water.
See these webpages for more information –
If you live on Lake Champlain, please consider becoming one of the LCC’s citizen volunteers and help us track algae this summer.