Keep the Magic Going
Cold Water Fish Species are Canaries in the Coal Mine for Climate Change
The Ducktrap River
Along the shore of Penobscot Bay in Midcoast Maine there is a Shangri-La for cold water fish species. It is a place of beauty and natural bounty that has been known to the Penobscot indigenous people since the Neolithic period. Legend states that Vikings arrived centuries before Captain John Smith landed in 1614. It became a site for colonial mills and early shipbuilding activity in America. However, this story is not about the past. It is about climate change and the impact today on native fish.
Hydrology
Sea Run Fish
Alewives
Salters
Atlantic Salmon
Conservation
Through the foresight, generosity, and hard work of over a dozen community-based, government, and academic organizations, more than 85% of the Ducktrap River watershed is now under protective easement managed by the Coastal Mountains Land Trust. CMLT actively manages and monitors the watershed for invasive plants and insects such as Japanese Knotweed and Hemlock woolly Adelgid. The current survival of its native fish populations is a testament to these extraordinary conservation efforts.
The Georges River Chapter of Trout Unlimited (GRTU), was previously known as the Ducktrap Chapter. Our chapter has long been involved in promoting the protection and conservation of the Ducktrap River. Our work includes land remediation and road culvert replacement. Beginning in 2022, in response to threats from climate change, GRTU initiated a fresh multi-year conservation program for the Ducktrap.
This initiative involves working with The State of Maine and NGO conservation groups to develop and deploy signage and educational materials along with an automated smartphone based Ducktrap Angler Survey Application.
eDNA Study Results
Water Temperature Results
Since the early 1980s, the rate of warming in the Gulf of Maine has been more than triple that of the world's oceans; 0.86 degrees F versus 0.27 degrees F.
In 2006 the Maine Department of Environmental Protection conducted a summer water temperature study of the Ducktrap River watershed.
Classification of streams to support cold water fish based on temperature in degrees celsius.
The larger streams without ponds and all of the smaller streams were found to be good sources of cold water to the mainstem. Streams with headwater ponds were relative sources of warm water. The conservation of cold water sources is extremely important. Land conservation is critical in order to preserve these cold water sources.
GRTU 2023 Summer water temperature study shows the mainstem and tributaries from feeder ponds warm to stressful levels for cold water fish in the summer months. However the smaller tributaries continue to be a life preserving source of cold water for Atlantic Salmon and Brook Trout.