Who is testing our lakes? We owe a great thanks to our dedicated group of Volunteer Lake Monitors, Lois Ruff on Lake Christopher, Carl and Cheryl Plassmann on North Pond and they have been monitoring Round Pond and South Pond as well, Kelly Bickford on Twitchell Pond with Vicky Gammon in training, and Rick Schneider on Indian Pond. None of the other ponds have volunteers so if you are interested, contact me, Jim Chandler, and we will connect you with Lake Stewards of Maine, formerly Volunteer Lake Monitor Program, for training.
In addition to this we had been hiring Scott Williams to do more tests on 2-3 lakes each year on a rotating basis. However we have been developing the capacity of our monitors and the Lakes Association to do many of the key tests on our own. Our goal also is to do the additional tests of phosphorus and dissolved oxygen and temperature profiles on each lake every year. With grant funding through Lake Stewards of Maine we were able to test 4 lakes for Total Phosphorus. We can now also take temperature and dissolved oxygen readings up to 50 feet deep thanks to a donation of a Dissolved Oxygen meter from Sunday River through Kelly Bickford. We hope to extend these measurements to all lakes each year in the future.
What tests do we take and what they can tell about lake quality ?: The Lake Stewards listed above take water clarity tests roughly every 2 weeks from May till September using a secchi disk. If the water is clear they can see it at a deeper depth than when the water is stirred up with sediment runoff or algae growth. It is a good overall measurement of lake conditions (similar to taking a pulse).
Phosphorous levels are important as they are the nutrient in least supply in lakes and control algae growth. Low levels of phosphorus result in little algae growth. Higher levels would indicate more sediment running into the lake, leading to higher algae growth which could then decay and reduce oxygen levels. If oxygen becomes restricted it can release phosphorus from the sediments in the lake and result in even more algae and degradation of water quality. Dissolved oxygen levels are crucial for the living things in the lake, and depleted oxygen over large areas of the lake can also release phosphorus from lake sediments. Dissolved oxygen measured at different depths along with temperature can tell a lot about the condition of the lake and what can live in the lake.
A summary of 2020 lake test results:
Lake Christopher (Lois Ruff) : Both deep spots in this lake are similar so we will focus on Station 1 towards the 4H Camp but the results are similar to station 2 at the other end of the lake. The lowest secchi disk reading was 3.27 meters on 05/15/20 and the highest value is 6.56 m on 9/10/20. The average 5.7 m with the historical value at 5 m. The low value was probably due to being close to when the lake turned over and is not representative of all other readings. The results show that Lake Christopher remains to be stable. The average clarity was a little better than average because much of summer was extremely dry.
The dissolved oxygen and temperature profile shows that the oxygen levels are depressed (< 5 ppm DO) below 8 meters deep and was depleted (< 1 ppm DO) below 14 meters. This is similar to past conditions. This also shows that Lake Christopher has the potential to have a larger area of the lake bottom with depleted oxygen. It is important to be vigilante in protecting or expanding vegetation buffer zones near the lake shore and along the streams that feed the lake. It is a good sign that the Total Phosphorus measurement was 3 ppb, which is substantially lower than historical averages of 8 ppb. This reduction is mostly due to the drought conditions at the end of the summer.
One other featured being observed is the presence of Gloeotrichia, a blue green algae that looks similar to green tapioca. It has been observed in Lake Christoper in the late summer for a number of years. This algae is not generally associated with nutrient rich waters but may increase as phosphorus is brought up to the surface from the bottom late in the summer. The levels currently observed is a 2 out of 6. This slightly higher than past years and is worth continued monitoring. Lake Christopher is the only lake in this region where Gloeotrichia has been observed.
North Pond (Carl and Cheryl Plassman) The lowest secchi disk reading was 5.23 meters on 06/25/20 and the highest value is 6.13 m on 9/12/20. The average 5.78 m with the historical value at 5.7 m. The secchi disk readings measuring lake clarity remain stable.
The dissolved oxygen and temperature profile shows that the oxygen levels are depressed (< 5 ppm DO) below 5 meters deep and was depleted (< 1 ppm DO) below 6 meters. This is similar to past conditions. North Pond is fairly shallow so the area of depleted oxygen is fairly small. However it is important to maintain or improve vegetation buffers around the lake and feeder streams, so the area of depleted oxygen does not grow. It is a good sign that the Total Phosphorus measurement was 4 ppb, which is substantially lower than historical averages of 8 ppb. This reduction is mostly due to the drought conditions at the end of the summer.
Round Pond (Carl and Cheryl Plassman) The lowest secchi disk reading was 4.85 meters on 06/25/20 and the highest value is 5.45 m on 7/18/20. The average 5.26 m with the historical value at 5.9 m. This average is a little lower than the historic average. This is worth watching but partly reflects the shallow nature of Round Pond.
The dissolved oxygen and temperature profile is about the same at the surface as it is almost to the bottom. There is little difference in the temperature at the top to the bottom for lakes less than 6 meters deep (20 ft). Shallow lakes of 20 ft or less get mixed by the wind and don’t develop a strong layering of temperature. In Round Pond there was only Dissolved oxygen levels < 5 ppm at the bottom near 6 meters deep. No Phosphorus test was taken this year.
South Pond (Carl and Cheryl Plassman) South Pond is the clearest lake in the association, that has a significant number of camps. Now that we have a DO meter it will be a good comparison to take measurements on those lakes occasionally. The lowest secchi disk reading was 7 m on 6/27/20 and the highest reading was 9.32 m on 09/12/20. The average reading this year was 8 m. The historic average is 8 m. This shows that South Pond continues to have excellent clarity.
The Dissolved Oxygen and Temperature Profile shows no depressed oxygen levels within 15 meters. Another indicator of low nutrient conditions in the lake which is excellent for cold water fish like trout.
Twitchell Pond (Kelly Bickford and Vicky Gammon) The lowest secchi disk reading this year was 6.1 m on 6/13/20 and the highest value was 7.15 m. The average was 6.59 m compared to the historic average of 6.7 m. This point to a higher than average water quality.
The Dissolved Oxygen and Temperature profile shows depressed oxygen levels below 6 m amd depleted oxygen below 15 m. This is good water quality but shows some signs of depressed oxygen levels. To keep up the good quality water it is important to have good vegetation buffers. Some good construction practices like silt fences were observed. The Total Phosphorus level was 3 ppm; which is very good and compares favorably to a 5 ppb historic average. This however is due to the drought conditions in the late summer this year.
Indian Pond (Rich Schneider) The lowest secchi disk measurement this year was 4.8 m on 5/17/20 and a high reading of 7.95 on 9/29/20. The average is 5.25 m compared to a the historic average of 5.7 m. This is a little lower but not significantly.
It will be good to do a Dissolved Oxygen Profile next year. A total phosphorus level of 3 ppb was taken on 8/24/20. This compares well to the historic average of 3.5 ppb. This shows that the watershed is well buffered and is this low even when the conditions are not dry.
Hicks Pond (Jim Chandler) Hicks Pond is a new measurement this year. Because it is shallow (max depth of 18 feet with an average depth of 7 feet. Like Round Pond it has about the same DO levels from top to bottom with oxygen a little depressed below 4 m. There is a lot of vegetation growing in the pond showing it is rich in nutrients. Because some lakes are shallow they are not often measured using the secchi disk.
Shagg Pond (Jim Chandler) Shagg Pond does not have a regular Lake Steward. I did one Dissolved Oxygen and Temperature profile this year. If anyone is interested they can contact the Lake Stewards of Maine for training. The profile taken 9/1/20 showed strong temperature layers changing around 6 m. The DO level was depressed (< 5 ppm) below 8 m and depleted near the bottom at 10 m.