Canada continues to be susceptible to biological invasion in a changing world. As a country, the area of freshwater covers 891,163 km2 and the length of the coastline—the longest in the world—totals 202,080 km. Alarmingly, many aquatic species have already invaded a wide array of habitats in Canada such as coastal salt marshes, freshwater lakes and rivers, estuaries, and coastal and open-water marine environments. For instance, the Great Lakes Basin is one of the world’s most highly invaded freshwater systems (Ricciardi 2006). These aquatic invaders represent many forms of life: bacteria, algae, vascular plants, invertebrates, and fishes. At least 17 terrestrial, mostly plants (Nunavut Government 2012), and 1 aquatic non-indigenous species, an alga (Mathieson et al. 2010), are currently established in the Canadian Arctic. However, intensifying research effort has recently found additional non-indigenous barnacles species attached to hulls of ships in Arctic waters (Chan et al. 2015). Although these temperate species are not locally established, they represent the future risk of aquatic species invading the Arctic.
- Ricciardi, A. 2006. Patterns of invasion in the Laurentian Great Lakes in relation to changes in vector activity. Diversity and Distributions 12: 425-433.
- Mathieson, AC, Moore, GE, and Short, FT. 2010. A floristic comparison of seaweeds from James Bay and three contiguous northeastern Canadian Arctic sites. Rhodora 112: 396-434.
- Nunavut Government. 2012. Non-native and invasive species in Nunavut. Department of Environment, Iqaluit, Nunavut, 2 pp.
- Chan, FT, MacIsaac, HJ, and Bailey, SA. 2015. Relative importance of vessel hull fouling and ballast water as transport vectors of nonindigenous species to the Canadian Arctic. Canadian Journal of Fisheries and Aquatic Sciences 72: 1-13.