The development of a rapid response plan to control the spread of the solitary invasive tunicate, Ciona intestinalis (Linnaeus, 1767), in Newfoundland and Labrador, Canada

摘要

The vase tunicate, Ciona intestinalis , was first confirmed in Newfoundland and Labrador (NL) waters in September 2012. The Department of Fisheries and Oceans (DFO) Aquatic Invasive Species (AIS) monitoring program, in collaboration with the Department of Ocean Sciences at Memorial University of Newfoundland (MUN), detected an isolated infestation of vase tunicate in Little Bay, Placentia Bay. The solitary tunicate was attached to wharf structures, eel grass, and some vessels in the area. Early detection of AIS is one of the primary goals of the DFO AIS monitoring program. This early detection, with the species currently confined to a small area of Placentia Bay, provided a unique opportunity for mitigation activities. This study details the various stages of a rapid response plan, its development through responses to two colonial tunicates, Botryllus schlosseri and Botrylloides violaceus , and its application to control the spread of solitary tunicate, C. intestinalis . Pre-invasion planning and the response plan include key phases of communication, detection and demarcation, containment and risk assessment, mitigation implementation and evaluation. Mitigation trials in Little Bay, Placentia Bay (2013 and 2014) have included floating dock removal, permanent structure cleaning, and recreational and commercial vessel cleaning with application of antifouling paint. Mitigated and unmitigated harbours have been monitored to evaluate the effectiveness of the control efforts. As of 2015, surveys of the mitigated area have only detected very small numbers of C. intestinalis , which were removed. A rapid response plan based on experience, good communication, strong partnerships, and common goals has allowed NL to respond to a high impact AIS tunicate in an effective manner. The new Aquatic Invasive Species Regulations in the Canadian Fisheries Act will provide authority for response, but monitoring, vigilance, prior planning, collaboration between stakeholders and rapid action are the real tools for an effective control plan.