Matt Verdirame – Lake & Dam Chairman
I am writing this to help our residents understand why a lake advisory was issued this past Friday. On Monday July 11 Aquatic Environments during their normal periodic testing of the lake took a sample from near the dam and sent it off to be tested. Friday, July 15 we were informed that the test showed that the levels of microcystins were elevated in that sample. Therefore the advisory was issued. If you are like me, you are likely now wondering “How did this happen and what are we going to do about it? The answer the first question is not very clear or simple because we are not really sure why the levels were high. Over the past couple of weeks the look of the lake has vastly improved with reductions in the “greenness” of the lake along with a corresponding reduction in fiberous algae in the coves combining with an increase in lake visibility. This was the result of the treatment of the lake with beneficial biologicals by Lake Savers. With these positive changes we would have expected to maintain a low level of microcystins. Even last year with the terrible algae blooms in August the microcystin levels were not elevated. So why they were elevated now we do not know.
John Doerr, a lake resident and microbiologist theorizes: “For what it’s worth, just reading some recent scientific publications on the topic. 1) microcystins are a group of 90 plus hepatotoxins (not neurotoxins). That means they affect the liver, not the central nervous system. 2) animals (dogs) and children will be the most susceptible to effects which result from drinking the water or eating contaminated sources (this could mean fish). In the presence of ‘pigments’, humic acid, etc. photodegradation can occur (e.g., sunlight penetration can be helping clear this out. But these toxins also adhere to sediments. We may actually be seeing results of movement of dead cyanobacteria from last year! Finally, while we don’t yet know the current distribution of the actual algae, I would highlight that these are toxins formed by blue-green algae and most of what people see in the water right now are benign green algae. When blue greens accumulate they will coalesce in long stringy masses at the surface which will have a very distinct, easily spotted cyan blue color (streaks of it).”
With the help of John, Aquatic Environments, and Lake Savers, we are continuing to research why the levels may be have been elevated.
The next question to be answered is “What are we going to do about it?
First we are retesting the lake. Aquatic Environments will be here on Monday July 18 to get new water samples. They will then freeze the samples and send the frozen samples off to a lab in Ohio to be tested. We are hoping to get the test results back by Friday. At that time depending on the results of the tests, we will either withdraw the advisory, or reissue it as indicated by the results. We are hoping, actually anticipating that the microcystin levels will be back down where they have been in the past.
Additionally, Lake Savers will be here next week to retreat the lake. As always when they are here they will check the aerators, treat the lake, and look the entire lake over for trouble areas and deal with these areas as needed and time permits.
I will continue to monitor the lake about every other day for any signs which indicate changes and continue to relay this information to Lake Savers.