Algae Season Recap
When it was bad, it was very bad. Photo by LCC monitor.
A crew of dedicated LCC volunteers fanned out along the shores of Lake Champlain each week to track the severity of blue-green algae blooms this past summer. To prepare volunteers, LCC provided 23 training sessions and for over 300 people in the late spring. The hours put into this program have translated into one of the most comprehensive monitoring programs in the country.
Volunteer monitors submitted a total of 1,487 reports of water conditions with an average of 99 reports per week during the regular reporting period (June 13 to September 18, 2015). This represents 79% of all observations submitted to the Vermont Department of Health (VDH) blue-green algae tracker (other reports came in from VDH and Department of Environmental Conservation staff). The number of reports per week peaked at 132 the week of August 15-21. One hundred different sites reported at least seven times during the regular reporting period.
Most of the weekly reports submitted by monitors indicated clear conditions (94%), 2% of reports were of low level blooms, and 3% were of significant blooms. As in years past, blooms were concentrated in northeastern bays. In Missisquoi Bay 18% of regular reports indicated blooms, while in St. Albans Bays 27% did. No other lake segment exceeded 3% of reports as blooms.
Blooms also have a seasonal pattern. Most appear later in the summer, and that was true in 2015 as well. The first blooms reported were the week of July 11 to 17, and the last two weeks of August had the greatest percentage of bloom reports.
This year for the first time we established regular monitoring locations at two inland Vermont lakes, Lake Carmi and Lake Iroquois. At Carmi we received reports from five different sites each week, while at Iroquois, which is much smaller, there was a single site at the south end of the lake. VDH also monitors the public beach on both lakes. At both lakes, 8% of reports indicated blooms, though at Iroquois this meant one report in the 13-week period. However, end of season blooms at Lake Carmi were significant with green lake water flowing out of taps drawing water from some sections of the lake.
