 |
Jody Jones (left) and Zoe Kitchel, the executive director and inaugural Railsback Fellow of Damariscotta Lake Watershed Association, respectively. (D. Lobkowicz photo) |
Buy this photo |
By Dominik Lobkowicz
Damariscotta Lake Watershed Association is participating in a new pilot program that will help bring “near real-time” water quality information on Damariscotta Lake into the
public eye.
The pilot program, run by the Maine Volunteer Lake Monitoring Program, selected 11 lakes around the state to test lake transparency using black and white “Secchi”
disks that are lowered into the lake to measure how far down one can see through the water.
Certified volunteers then upload the data to http://mainelakesdata.org, where anyone can visit to see the most recent data
within 24 hours of the reading.
A decrease in water transparency can be an indicator of increased phosphorus in the lake, which could eventually lead to an algal bloom and subsequent fish kill if
unchecked, according to DLWA staff.
Too much phosphorus – as little as 20 parts per billion – can lead to algal blooms, which can lead to fish kills due to lack of oxygen in the lake, according to DLWA
Executive Director Jody Jones.
Damariscotta Lake has an average of 9 to 11 parts per billion of phosphorus, but individual measurements have been as high as 14, “which we think is too close to
20,” Jones said.
According to Zoe Kilcher, the DLWA’s inaugural Railsback Fellow, additional photosynthetic organisms at the top of the lake – the algae – eventually die and sink.
Organisms at the bottom of the lake eat the dead algae and in turn use more oxygen, depleting oxygen levels, she said.
Trout and land-locked salmon would both be affected by this lack of oxygen, Jones said.
“One you have an algal bloom, it’s expensive and difficult to turn it around,” she said.
An important part of the monitoring is comparison with the lake’s own data over time, Kilcher said. Under the pilot program, Secchi disk reading will take place
every couple of weeks.
Since May, the Secchi depth for Damariscotta Lake has ranged from as deep as 5.34 meters to as little as 4.35 meters.
For Damariscotta Lake in particular, “anything less than three meters, you start getting worried,” Jones said.
Other particulates can affect transparency too, Jones said, such as pollen or sediment.
The association has been collecting this type of transparency data for 15 years, but once submitted to the state and the volunteer monitoring program, the data is
not readily accessible, Jones said. Now, the data is viewable online within a day.
With the past availability of data, there has been a “missing link” since the numbers change both year to year and through the course of a season, Kilcher said.
Having the near real-time data will help people feel more connected to the lake and what is actually going on within it, she said.
According to Jones, one of the reasons Damariscotta Lake was selected was because of the watershed association’s reliable staff.
“The quality of the data has to be assured,” she said.
The DLWA does do phosphorus testing as well, which is more expensive, Jones said. In past years such testing was only done in the fall, but starting this year
testing will be done in July, August, and September, she said.
“We want to improve the water quality and avoid some of the disasters that have happened in other parts of the state,” Jones said.
Jones said the DLWA recognizes that monitoring is not all that needs to be done, and sources of phosphorus need to be identified and stopped.
The association recently completed a survey of the watershed with over 99 percent landowner participation, so the DLWA has good information on erosion sites in the
watershed – a source of phosphorus – and will be working to remedy those problems, Jones said.
The survey yielded 29 sites which have a high impact on the lake, and those sites alone release 63 tons of sediment and 61 pounds of phosphorus into the lake each
year, according to a fact sheet on the survey.
Information gathered in the initial survey will be continually updated going forward, Jones said.
For more information on DLWA or the watershed survey, visit http://www.dlwa.org.
