Grant: Strategic Projects - Group

Invasive species are among the most important anthropogenic components of global change. Shipping has led to a global homogenization of the distribution of species, resulting in catastrophic reduction in native species biodiversity with severe economic consequences. Invasive species have caused large reductions in native species biodiversity on the east and west coasts of Canada and have reduced the sustainability of aquaculture. We have discovered two species of invasive colonial ascidian tunicates in several harbours on the south coast of Newfoundland. They have not yet attained high densities however, providing the rare opportunity to conduct 'pre-invasion' research and increasing the probability of successful mitigation. Our first objective is to develop TaqMan gene probes and real-time PCR assays, permitting early detection of a single ascidian egg or larva in a plankton sample. These probes will be based upon the nucleotide sequence of the cytochrome oxidase I gene of mitochondrial DNA, a reliable indicator of species identity. The gene probes may be made commercially available in 3-5 years. Successful eradication also depends upon knowledge of which mitigation measures to apply and where and when to apply them. Thus, mitigation must be guided by knowledge of the population dynamics of the invader. Our second objective is to conduct an annual investigation of the population growth and recruitment potential of Botryllus schlosseri in Placentia Bay, and the potential reinvasion of Botrylloides violaceus into a mitigation area in Belleoram. We will develop a 'best practices' protocol document, enabling government managers to make more informed decisions about invasive ascidian eradication. The applied research we propose will help managers conserve native biodiversity of Canadian coastal waters, ensuring that economic, recreational and asthetic benefits will be sustained for future generations.