Space invaders: searching for invasive Smallmouth Bass (Micropterus dolomieu) in a renowned Atlantic Salmon (Salmo salar) river

Humans have the ability to permanently alter aquatic ecosystems and the introduction of species is often the most serious alteration.  Non-native Smallmouth Bass (Micropterus dolomieu) were identified in Miramichi Lake c. 2008, which is a headwater tributary to the Southwest Miramichi River, a renowned Atlantic Salmon (Salmo salar) river whose salmon population is dwindling.  A containment programme managed by the Department of Fisheries and Oceans, Canada (DFO) was implemented in 2009 to confine Smallmouth Bass (SMB) to the lake.  We utilized environmental DNA (eDNA) as a detection tool to establish the potential escape of SMB into the Southwest Miramichi River.  We sampled at 26 unique sites within Miramichi Lake, the outlet of Miramichi Lake (Lake Brook), which flows into the main stem Southwest Miramichi River, and the main stem Southwest Miramichi River between August and October 2017.  We observed n=6 positive detections located in the lake, Lake Brook, and the main stem Southwest...