Update 7/9/10 - Algae Bloom in Lake
- Algae bloom in Town Farm Bay, Charlotte 7/6/10. Photo by Pete Rosenfeld
Our blue green algae monitoring program got underway this week with citizen monitors taking samples at 18 shoreline locations. The current hot, steamy weather conditions are ideal for algae growth and they’ve led to extensive algae blooms particularly in Addison (VT) and Essex (NY) counties. Blooms have been reported in many areas from Burlington south to the Crown Point Bridge area, including Port Henry, Westport, Panton, Ferrisburgh, Kingsland Bay, Long and Thompson’s Points, around Juniper Island in the Main Lake and other locations. Shifts in wind and water currents will move the blooms around the lake and scums may accumulate on the shoreline so keep a watch on the water.
Preliminary Test Results
Analysis of water quality samples done at the University of Vermont Lab indicate the following:
- All sections of the Northern Lake, Missisquoi Bay, St. Albans Bay and the Inland Sea currently have very low densities of potentially toxic cyanobacteria. These sections of the lake are generally considered safe.
- Preliminary test results from other areas of the lake indicate patchy occurrences of potentially toxic algae concentrations. Only very low levels of actual algal toxins have been detected however.
Take Precautions
Not all blue green algae blooms contain toxins but the general rule is – stay out of the water if it looks unappealing. Anyone recreating on or near Lake Champlain should watch for and avoid dense accumulations of algae. Children are at higher risk because they are more likely to drink the water. Keep pets away from algae-contaminated water to avoid them drinking it and consuming algae on their fur. Check your intake pipe regularly if you get water from the lake. If there’s algae in the vicinity, switch to an alternate safe source of water. Boiling water will not remove toxins.
Stay Informed
For the latest updates on algae conditions on Lake Champlain, visit the Vermont Department of Health website. To help people distinguish blue green algae from other floating phenomena in the lake, the Lake Champlain Committee has prepared a pamphlet recognizing blue green algae in Lake Champlain (pdf).
LCC Blue Green Algae Monitoring Program
- A blue green algae monitor taking a sample at North Beach.
Photo by Lori Fisher
Each summer since 2004 LCC has partnered with the University of Vermont Rubenstein Lab, to expand blue green algae monitoring on Lake Champlain. LCC helps train and oversee citizen monitors who take weekly water samples from select shoreline areas. We also monitor several shoreline beaches, do visual site checks at additional locations, and serve as a first responder when blooms are underway. This program, which LCC initiated, provides critical data on where and when blooms are happening. The information we gather is used by public health officials to assess whether the water is safe for swimming. Volunteer monitors go out once per week from early July through Labor Day to collect samples and take them to designated drop-off locations.
What You Should Do If You See A Bloom
If you witness a bloom in your area, please report the information to LCC at 802-658-1414 or lcc@lakechamplaincommittee.org.
Please include the time, date and location of your sighting as well as a description of what you observed and the extent of the bloom and your contact information.
Homeowner toxin test kits can be purchased for $20 by Vermont residents at the Vermont State Health Department Laboratory at 195 Colchester Avenue in Burlington or over the phone by credit card by calling 800 660-9997 ext. 2.
About Blue Green Algae
(From the Vermont Department of Health)
Blue-green algae, (cyanobacteria) are a common and natural component of the microscopic plants (plankton) in Lake Champlain. Some kinds of blue-green algae produce natural toxins or poisons. When these algae die and break down, toxins can be released into the water.
If animals ingest the toxin, they can be quickly paralyzed and die. Signs of poisoning include weakness, staggering, difficulty breathing, convulsions and death. Although there are no documented cases of human illness related to blue-green algae in Lake Champlain, during the summers of 1999 and 2000 the death of two dogs was attributed to blue-green algae poisoning, after drinking large amounts of contaminated water directly from the lake.
Blue-green algae can become very abundant in some sections of Lake Champlain once the water warms up in mid-summer. Particular problem areas are Missisquoi Bay and St. Albans Bay. Under calm conditions, blue-green algae can accumulate in thick layers at the surface or along the shoreline. These accumulations are frequently referred to as “blooms” or “scums.”
While blue-green algae toxins have been detected at many locations in Lake Champlain, the highest concentrations of toxins are usually found in blooms and shoreline scums. These dense accumulations pose the greatest potential risks to people and pets.
Weather influences where blue-green algae will accumulate in a given location. During extended periods of calm and sunny days, blooms can accumulate at the surface in any location. Wind and waves may cause them to form along shorelines or in protected areas. Shifts in wind direction can move a bloom from one location to another. Periods of cool rainy weather can often lead to the disappearance of a bloom.
Blue-Green Algae
In recent years, toxins produced by certain blue-green algae species have been found in Lake Champlain. Algae toxins present a potential hazard to swimmers and their pets, and could affect drinking water collected during bloom periods.
However, not all algae produce toxins, and even those species that can produce toxins do not do so in all instances. Lake Champlain’s algae blooms are most likely to occur in shallow bays in the northeastern portion of the lake. Deep, cold water locations with fewer nutrients, such as the Main Lake, are less likely to support blooms.
Nuisance algae blooms result from too much phosphorus pollution in the lake. Reducing pollution is the key to minimizing future blooms. The Lake Champlain Committee’s work helps the pubic better understand the risks associated with blue-green algae blooms.
LCC's Past and Ongoing Projects
- Raised awareness of increase in blue-green algae blooms and pushed for research and monitoring to understand causes.
- Established and run a volunteer monitoring program in cooperation with the University of Vermont, designed to determine when algae blooms appear to be producing toxins and to inform the public through relevent health agencies when toxic blooms occur.
- Produced a brochure to help distinguish blue-green algae (PDF, 450K) from other algae species and other floating phenomena in Lake Champlain.
- Conduct weekly surveys of public access points around the lake during the summer and report on algae bloom conditions.
Algae Monitoring Results Summary
Results from the Lake Champlain Committee's volunteer water monitoring program provide insight into the levels and locations of nutrient pollution. In 2009, significant algae blooms developed in Missisquoi Bay, in the northeast section of the lake. Additional blooms were noted sporadically throughout other parts of Lake Champlain including St. Albans Bay and Red Rocks Park in Burlington.
In total, there were 19 "low alerts" and three "high alerts" issued during the 10 weeks of citizen monitoring. High alerts occur when there are dense algae scums, and toxins are above levels of concern. Low alerts occur when the density of potentially toxic species is high, but the actual level of toxins is below levels of concern.
Missisquoi Bay saw three high alerts and 13 low alerts at the four volunteer monitoring sites, St. Albans Bay saw two low alerts, and an additional four low alerts were issued in other parts of the lake.
Comparison with recent years
| year | low alerts | high alerts |
|---|---|---|
| 2009 | 19 | 3 |
| 2008 | 21 | 3 |
| 2007 | 6 | 0 |
| 2006 | 48 | 3 |
| 2005 | 21 | 3 |
