Non-indigenous tunicates in the Bay of Fundy, eastern Canada (2006–2009)

Abstract

A monitoring programme was initiated in 2006 to detect invasive tunicates, especially Ciona intestinalis, Botryllus schlosseri, Didemnum vexillum, Botrylloides violaceus and Styela clava, in Atlantic Canada. Collectors were deployed at 11–21 monitoring stations in the southwestern New Brunswick portion of the Bay of Fundy from 2006-2009, starting in late May with some retrieved in August while others remained in the water until later in the fall. There was large variability between years and sites. C. intestinalis was detected through much of the southwest New Brunswick area, including Grand Manan Island, but not in the area from Dipper Harbour to Saint John. B. schlosseri was observed to be concentrated in the Dipper/Beaver Harbour areas and Grand Manan Island, St. Andrews Harbour, Fairhaven (Deer Island), and Harbour de Loutre (Campobello Island), with greatest settlement observed in 2009. During the study period, B. violaceus was first detected in 2009 and at only one location, Head Harbour, Campobello Island. S. clava and D. vexillum have not been detected from our sampling collectors to date. As the invasive colonial tunicate, D. vexillum, has rapidly extended its range in the northeastern United States of America and is within 2 km of Canadian waters, a rapid assessment was conducted around Deer Island and Campobello Island in September 2009 and failed to detect the species.