Not all cyanophytes have toxins. There is a diverse set of species living in Lake Mendota when the water has warmed and the nutrients pour in as they have in the last week. An extensive bloom can cause a decrease in dissolved oxygen in the waters because the bacteria decomposing the dying bluegreen algae need and use oxygen in the process. Sometimes this also causes a fish kill if the dissolved oxygen levels become too low.
The Dane County muck removal project to remove phosphorus loaded sediments from the lower reaches of streams near near their outlet to Lake Mendota, will reduce the phosphorus that enters from these storms. It should have a more immediate effect than, for example, cleaning up a particular farm high in the watershed."
The blue-green algae bloom forced the closure of several Madison-area beaches including a stretch of Lake Mendota from UW-Madison to Middleton. Kynala Phillips reported in the Wisconsin State Journal. She also interviewed Jeff and Arlene and you can read last weeks front page article about the issue in the Wisconsin State Journal.
The Public Health Department takes water samples weekly, but the department also depends on citizen reports and organizations like the Clean Lakes Alliance to get a real-time understanding of the lakes’ conditions.
You can learn more on July 11, 9:05 am, when Trina Mahon will speak about Blue-Green Algae Bloom at the monthly Yahara Lakes 101 event organized by Clean Lakes Alliance (at the Edgewater Hotel).
Arlene is consulting with a host of scientists and government agencies in an effort to summarize the causes, toxins released, effects, and possible actions regarding cyanobacteria blooms on our lakes. – Gisela