Have you noticed that every other Monday there has been a boat out in the middle of Wilson Lake with several people doing some strange looking activities? For many years our own Dan Orino has been testing the clarity, dissolved oxygen and temperature of the lake and reporting the data to Maine’s Volunteer Lake Monitoring Program to provide a long term picture of what is happening to the lake. This year we have taken advantage of the opportunity to be part of a pilot program being conducted in the Acton Wakefield area by the University of New Hampshire and the Acton Wakefield Watersheds Alliance. UNH has provided an intern, Erich Berghahn, to work with WQ volunteers on Wilson, Lovell, Great East and Ivanhoe Lakes and Horn Pond on a regular basis to conduct extensive tests of the water. These test include the usual Secchi Disc (clarity), DO (dissolved oxygen), and temperature, but also add tests for turbidity, conductivity, alkalinity, phosphorus and chlorophyl-a. Water samples are collected and tested at 1/2 meter intervals. It’s a fascinating process and one in which we are excited to be participating. Erich takes the samples back to the UNH lab for analysis and the phosphorus and chlorophyl-a are sent out for analysis at a nominal fee to participating lake associations.
In addition to Dan Orino, other Wilson Lakers who are volunteering to be a part of this program are Heidi and Arlie McGaw, and David and Diana Spahn. These folks have offered to be available to help conduct the experiments with Erich if Dan is unavailable. Wilson Lake Association is proud to have members who care so deeply about preserving the water quality of our lake.
Hi,
i am a chemist and a fisherman….I was very concerned about the disssolved O2 concentration reported in your report. According to my data , fish cannot survive at that O2 level, we should investigate a little further and find out
1.what this means for fish to survive over the winter,
2. why this is
3. can anything be done?
4. should we take another measurement?
How does raising and lowering the lake levels affect this
please reply
thanks
ron, peacock road
Hi Ron,
Thanks for your careful attention to the WQ testing.
The results are not surprising as we have been aware of the decline in DO which occurs every summer as the water temp increases as August approaches.
Part of the reason for this is that we have a very slow flushing rate. That is the replacement of all the water in the lake as new water from streams enters.
If you still have a copy of our May, 2013 Newsletter, there is an article about stratification which causes temperature layers in lake water to flip twice a year. As a result, the flip causes the upper layer (the epilimnion) with a good mix of oxygen, to switch with the poorly oxygenated water (the hypolimnion) at the bottom. In very shallow lakes this stratification does not occur. Wilson Lake is deep enough, about 50 feet at its deepest, to allow this flip to occur.
You are correct that low oxygen levels at the deeper levels are stressful for cold water fish such as trout.
This process has been going on in Wilson Lake for many years as has been shown by the testing completed by Dan Orino.
The raising and lowering of the dam does not negatively affect the temperature or the oxygen levels of the lake. We would have a better flushing rate if we had more streams bringing oxygenated water into the lake, however this is not something we can control.
You can access the article by going to our website, http://www.wilsonlake.net, and clicking on the newsletter for Spring 2013.
I hope this helps, though, I’m sad to say Wilson will probably never have a large number of trout and salmon because of the nature of our depth and flushing rate. I have been fishing and caught brown trout out on the lake, though it is a rare occurrence.
Meanwhile, we can all do our part to maintain and improve our water quality by caring for our own properties and eliminating soil erosion and introduction of phosphorus into the lake. Every little bit we do to preserve our water quality protects our recreational and esthetic benefits.
I hope this helps. Have a great summer on the lake!