Results

Summary

Upon completion of data collection six plants that were collected were considered of notable presence. Of these six it was determined that the nuisance plants that exist in the middle of the lake, otherwise known as submerged plants were Eurasian watermilfoil and small pondweed. They were found in approximately equal and sizable quantities. As these collections were done in late fall it is important to note that collections in spring or summer will see much higher density readings due to the plants extending towards the surface as well as increasing surface area to gather as much light as possible. Eurasian watermilfoil seems to be the plant that is spreading the fastest throughout the shallow areas of Indain Lake. Of the shoreline emergent plants, the two most frequent were common reed and cattail. Both of these were found in approximately equal quantities. In 2004 small pondweed was not identified at all on Indian Lake and cattail had only a slight presence, however in 2012 they were both very prevalent in certain areas of the lake and should therefore be watched carefully. Since 2012 it appears that they did not spread anymore and in fact were found in less areas of the lake.

Certain conditions were also observed during collections that have proven to help the growth of these plants. No plants were identified in any area of the lake deeper than eight feet in any survey. It was also identified that most areas affected by plant overgrowth were areas of the lake cut off from current flow. The shoreline of the lake was noted as being a large problem in 2015. Many of the weeds collected were emergent plants along the shoreline, blocking the view of the lake from landowners. It does not seems as if these emergent plants have spread to different areas of the late, however the main issue is that there seems to be no imporvement from 2013.

Data Mapping

With the data collected during the survey, a Google Earth interactive map was created to indicate each plant's presence within the lake. Each plant was assigned a unique color, a collection point without plant life was recorded as a white dot. This information was separated into multiple maps to make each one easier to understand. The same procedure was for the 2015 survey in order to keep the information capatable. For initial analysis all of the data was layered over one map to discover any relationships between different data points. Both surveys were added to the same map to show the distribution changes over the years. Using the Google Earth maps we created, a few notable correlations were found. Though the lake extends beyond 20 feet deep in some, no plants were found in water deeper than 7 feet. We also found that areas cut off from constant current flow, such as the area south of Sear's Island, were prime locations for invasive weed overgrowth in both surveys. The lack of current flow in areas affected by overgrowth suggests that stray current flow may deposit silt and other nitrogenous soil particles in these areas of the lake. Because there is no steady flow there to remove the silt this results in a buildup of soil that promotes plant growth. These maps can be found in the MAPS section, or through the links under results on the left side of the page.

Stenciling

Adding a spray paint stencil to each storm drain that leads to Indian Lake provides awarness to the community of the risks of dumping down the drains. The 2015 team stenciled 138 drains with material provided by the City of Worcester. All together, about 47% of the storm drains leading to Indian Lake are known to be stenciled, however this number may be higher. The interactive data map provided by google maps gives the full outline of the map (red) provided by the City of Worcester showing the storm drains leading to Indian Lake. The green patches encompass the streets and areas in which the drains have been stenciled. If any area located on the map has drains that need to be stenciled or re-stenciled, please contact the ILWA.


Developed as Part of a WPI Sponsored Project
In Affiliation with The Indian Lake Watershed Association
Worcester, MA 2013