Turmennan is the only transition mire in the CANN project, and is one of the best examples of this habitat type in Northern Ireland. It was once ear-marked as a potential landfill site but was designated as an ASSI in 1999.
This wetland, like many wetlands, exists as an “island” within the intensively farmed agricultural landscape of County Down.
Notable plants such as Marsh St John’s Wort, Floating Club Rush, and Least Bur-reed can be found at Turmennan. The site is also a wetland haven for insects, with 39 aquatic beetle species recorded here, as well as the endangered Marsh Fritillary butterfly.