About 150 people attended Water Summit 3 hosted by the Wentworth Watershed Association. An impressive set of speakers let us know the good, the bad and ugly about Cyanobacteria. These are not actually algae, they are bacteria that evolved billions of years ago. At that time, there was literally no oxygen in the Earth’s atmosphere or they ocean so they evolved to live with out it. For this reason, they can presently survive where other organisms can’t. Lake Wentworth has low oxygen levels at the bottom during the summer. These bacteria are able to thrive in this environment and are stimulated to grow by phosphorus that settles to the bottom of the lake from storm water run-off. When the water mixes in the late summer they rise to surface and can cause large clusters or mats of bacteria called blooms. These blooms can produce toxins that are harmful to humans, pets and other organisms. This is not a new phenomenon, but the frequency and size of the blooms are increasing. We need to worry about them…
The cyanobacteria have an interesting life cycle in that they tend to not be an issue until mid to late summer in our area. Then, they may come to the surface and cause problems. Often, in the middle of the lake, they are hardly visible but the wind can move them into bays and they form a green scum. In these concentrations, people should be aware of risks associated with them and avoid jumping in, letting pets jump in, or drinking the water. Last Summer, this was a very real problem in Lake Winnipesaukee’s Winter Harbor.
Bacteria need phosphorous to grow, any addition of phosphorous to our lakes increases their growth leading to blooms which are bad for lake health. This is why you should never use fertilizer on your lawns that has the middle number other than a “0”, which means no phosphorous (phosphorous makes plants want to bloom and you don’t need your grass to bloom). Basically, when it rains. storm water enters the lake, the more phosphorous carried by the water from any source such as lawns, septic, or pet waste increases the risk of larger blooms of cyanobacteria.
All of us are part of the solution. We each need to reduce the amount of storm water run-off going into the lakes because the water takes sand and soil and phosphorous with it. This is why members are building rain gardens or areas where storm water can collect and seep into the ground instead of flowing directly into the lake. Information about ways to infiltrate water on your property is available through DES Soak up the Rain resources or at the Association office. Additionally, the Town in collaboration with DES, EPA and the Association are working on Best Management Practices or storm water solutions to address major issues in the watershed that were identified and prioritized in the 2012 Wentworth- Crescent Watershed Management Plan.
We also need to identify previously unknown erosion areas during storms, monitor for blooms, and collect samples when blooms are present. The town is hosting a cyanabacteria monitoring and testing workshop which is being held at the Brewster Academy Boathouse from 9:30-11:30 on Wednesday, June 26th. If you haven’t signed up for this training, and would like to be a monitor or tester, please contact the office to sign up. No scientific background is required, just a desire to help. The Wentworth Watershed Association has a cyanoscope in the office that trained monitors can use identify which species of cyanobacteria are present in a water sample. This information can help determine if they sample needs to be sent off to a lab for immediate toxicity testing and health hazard alerts need to be emailed out to members and posted at beaches.
Hear from cyanobacteria and lake experts to learn about how these bacteria are a threat to lake health and your health. Part one includes Dr. Hanney’s informative presentation. Watch part two to hear about each of Wolfeboro’s waterbodies health and what you can to get trained and help monitor for cyanobacteria this summer.
Below, Don Kretchmer is asking questions from the audience of the three main speakers.