O'Sullivan Antóin M, Samways Kurt M, Perreault Alysse, Hernandez Cécilia, Gautreau Mark D, Curry R Allen, Bernatchez Louis
Canadian Rivers Institute University of New Brunswick Fredericton NB Canada.
Faculty of Forestry and Environmental Management University of New Brunswick Fredericton NB Canada.
Ecol Evol. 2020 Feb 15;10(5):2588-2596. doi: 10.1002/ece3.6088. eCollection 2020 Mar.
Humans have the ability to permanently alter aquatic ecosystems and the introduction of species is often the most serious alteration. Non-native Smallmouth Bass () were identified in Miramichi Lake . 2008, which is a headwater tributary to the Southwest Miramichi River, a renowned Atlantic Salmon () 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 = 6 positive detections located in the lake, Lake Brook, and the main stem Southwest Miramichi downstream of the lake. No detections were observed upstream of the confluence of Lake Brook and the main stem Southwest Miramichi. The spatial pattern of positive eDNA detections downstream of the lake suggests the presence of individual fish versus lake-sourced DNA in the outlet stream discharging to the main river. Smallmouth Bass were later confirmed by visual observation during a snorkeling campaign, and angling. Our results, both eDNA and visual confirmation, definitively show Smallmouth Bass now occupy the main stem of the Southwest Miramichi.
人类有能力永久性地改变水生生态系统，而物种引入往往是最严重的改变。2008年在米拉米奇湖发现了非本地小口黑鲈（），米拉米奇湖是西南米拉米奇河的源头支流，西南米拉米奇河是一条著名的大西洋鲑鱼（）河流，其鲑鱼种群数量正在减少。2009年，加拿大渔业和海洋部（DFO）实施了一项控制计划，将小口黑鲈（SMB）限制在该湖中。我们利用环境DNA（eDNA）作为检测工具，以确定小口黑鲈是否有可能逃到西南米拉米奇河中。2017年8月至10月期间，我们在米拉米奇湖、流入西南米拉米奇河干流的米拉米奇湖出水口（布鲁克湖）以及西南米拉米奇河干流的26个独特地点进行了采样。我们观察到在湖中、布鲁克湖以及湖下游的西南米拉米奇河干流中有6次阳性检测结果。在布鲁克湖与西南米拉米奇河干流交汇处的上游未观察到检测结果。湖下游阳性eDNA检测的空间模式表明，在排入主河的出水溪流中存在个体鱼类而非源自湖泊的DNA。后来在一次浮潜活动和垂钓过程中通过目视观察证实了小口黑鲈的存在。我们的结果，无论是eDNA还是目视确认，都明确表明小口黑鲈现在已占据西南米拉米奇河的干流。
