Update On Invasive Plants

As of 10/13/2023

SINCE OUR LAST UPDATE, EVEN MORE EURASIAN WATER MILFOIL (EWM) HAS BEEN FOUND.

Note: While this update is is incredibly disappointing, it is important to remember that EWM would be silently spreading to uncontrollable levels without the support and great work done to date. If we work together and all do our part, we can contain the spread. Other lakes have succeeded and we can too!

Friends of the Cobbossee Watershed staff has pulled individual plants whenever possible and Maine Department of Environmental Protection is being called in to investigate other areas as necessary. Listed are the spots in which EWM has been found to date. Please avoid these areas for now:

  • Cobbossee Outlet by the bridge to the dam

  • Cobbossee Stream

  • Horseshoe Island

  • Farr’s Cove

  • East Winthrop Public Boat Launch

  • Hammond’s Grove

  • Pine Point Lane

  • Upper Sister Island

  • Frog Island

These areas are highlighted in red on the map to the right. The diamonds indicate plant clusters and the circles indicate single EWM plants. You can also check an  interactive map to look at these areas more closely.

In addition to the areas marked on the map, we expect that EWM to be in other shallow areas up to 15' deep around our islands and shoreline. And it will continue to grow aggressively throughout October.

SEVERAL actions have been taken to mitigate the spread:

1) DEP used an herbicide treatment in the Outlet Cove and the area between the bridge and dam. (See the photos and information below). In addition, DEP and IF&W have issued a Surface Use Restriction (SUR) for the area between the bridge and dam. This restriction applies to all watercraft -- canoes, paddle boards, kayaks, jet skis and boats. Please see the notice and map below for details. For further information contact John McPhedran, Biologist at Maine DEP at 207-215-9863 or John.McPhedran@maine.gov

WARNING: There is a fine of $500-$5,000 for taking any watercraft into the SUR area.

2) Due to the broad nature of the scattered spread of EWM in the other areas identified, DEP has determined that these areas do not lend themselves to isolation with warning buoys or SUR buoys. Known plants have been removed. Extensive surveys of these locations continue and we ask everyone to treat these areas as potentially harboring more EWM plants.

3) Friends staff and CLA volunteers continue to survey for additional plants. When single plants are found, such as those on the west side of Horseshoe Island and within Horseshoe Cove, Friends divers remove them as quickly as possible.

4) Communications to our lake community, including handouts provided to boaters at the private and public launches, educate about the areas to avoid on the lake.

SURFACE USE RESTRICTION (SUR) ESTABLISHED ON JULY 26, 2023.

HERBICIDE TREATMENT APPLIED TO COBBOSSEE ON AUGUST 11, 2O23

Above left: An airboat treating the area on THE LAKE SIDE OF THE BRIDGE.

Above right: Another boat mixing the herbicide treatment for the area FROM THE BRIDGE TO THE DAM.

YOU CAN HELP PROTECT COBBOSSEE BY TAKING THESE STEPS:

1) Observe the watercraft “Surface Use Restriction” (SUR) in the area between the Outlet bridge and dam. (More about this below)

WARNING: There is a fine of $500-$5,000 for taking any watercraft into the SUR area.

2) Stay away from shallow coves and areas along the shoreline and islands up to 15 feet. EWM is very fragile and fragments are easily broken off by a prop, anchor, fishing line, paddle, or swimmer -- and those fragments will re-root and aggressively spread. 

3) Notify Friends of the Cobbossee Watershed if you think you have found EWM. Do not remove the plant; instead email a photo of it along with the location and date to Alex at Alex@watershedfriends.com

4) Use the public launches or Lakeside Marina and Birches and cooperate with boat inspections at each of these locations every time you put your boat in and take it out.

5) If you come to a launch without an inspector, do your own inspection. Follow the "Clean. Drain. Dry." protocol outlined by the state here.

6) Spread the word! We can't close down the lake (and certainly don't want to), and we can't mark every at-risk area along the shoreline, but we can spread the word and urgency. So tell you friends, neighbors, renters – make them all aware. Share this web page with them.

7) Stay current on what's happening in the lake. We will continue to send emails to our members as new information is available. And you can visit this website at any time for the most current information.

The sign above designates areas where FOCW’s teams are still removing or otherwise managing invasive species. Please stay away from these areas to allow them to manage the infestation most effectively.