Swollen Bladderwort

Pleasant Pond, Maine — In a significant development, a new aquatic invasive plant species has been identified in the Cobbossee watershed. The diligent efforts of our Courtesy Boat Inspectors and conservation teams have led to the discovery of an unidentifiable bladderwort species removed from a motorized boat exiting the Pleasant Pond boat launch this month. Prompted by this finding, the Friends team conducted a swift follow-up survey and confirmed the presence of Utricularia inflata, commonly known as Swollen Bladderwort, around both the upper and lower boat launches.

Swollen Bladderwort, a free-floating submerged plant native to the Atlantic and Gulf Coastal plains, was recently added to Maine’s “watch” list of Aquatic Invasive Species. It has the potential to spread rapidly as small fragments can hitch a ride on motorized boats, fishing gear, and other recreational equipment. This invasive species has now been documented in four additional waterbodies across Maine.
This discovery highlights a broader trend in the Courtesy Boat Inspection program’s findings this season. Our inspectors have conducted over 7,000 boat inspections so far, identifying and removing invasive species from several vessels. These efforts include the removal of Curly Leaf Pondweed from a boat entering Cochnewagon Pond, Eurasian Water Milfoil from a boat visiting Cobbossee Lake from another state, and European Frog’s-bit from a boat exiting Cobbossee Lake.

The detection of Swollen Bladderwort at Pleasant Pond marks the Cobbossee Watershed’s fourth known aquatic invasive plant. To assess the extent of the infestation, the Friends team will conduct a comprehensive survey of Pleasant Pond in the coming weeks. Collaborating closely with the Maine Department of Environmental Protection, the Friends aim to integrate this species into the overall management plan for Pleasant Pond, which has been dealing with Variable Leaf Milfoil since before Friend’s began staffing the launch with CBIs in 2003.

The Friends of the Cobbossee Watershed remain committed to preserving the health and biodiversity of our waterbodies. We extend our gratitude to the Courtesy Boat Inspectors and all volunteers who contribute to these crucial efforts. Public awareness and cooperation are vital in preventing the spread of invasive species and protecting our natural resources.