Aquatic Invasive Species

Aquatic Invasive Species (AIS) are species that invade a habitat where they were not previously present, and may cause changes to the established structure and function of the invaded ecosystem. The objectives for research in this area are to (i) understand how AIS affect physical and biological components of coastal habitats, (ii) determine ways to minimize or prevent AIS from invading a habitat, and (iii) identify options that reduce the impact on habitat from established AIS.

Since 2003, research has been conducted on the vase tunicate, Ciona intestinalis, with a focus on: (a) understanding their basic life cycle and population dynamics; (b) identifying biological control points and the associated environmental cues; and (c) investigating ecological interactions between tunicates and mussel aquaculture. A second avenue of research is the study of population diversity of C. intestinalis, including genetic studies to analyze population structure and gene flow between bays in infested areas in order to determine the possible origin of existing populations and identify invasive pathways of new populations. An ongoing tunicates monitoring program, established in 2006 along the Nova Scotia coast, continues to provide information on the distribution (spatial and temporal) and level of infestation of five species of tunicates. This program has established a framework for community based environmental stewardship and education. Other areas of AIS research focuses on the European green crab. Laboratory and field experiments are being used to study green crab predation on commercially important shellfish. Also, the impact of green crabs on coastal habitats and biodiversity is being studied. Furthermore, research will continue to investigate the successful characteristics of AIS and the invading environment in order to assess the risks of potential invasion of new species from vectors such as ballast water.