Invasive alien species are disrupting and changing the normal ecological functions of biomes, ecosystems, and the biosphere as a whole (CBD, 2009). They are a threat to biodiversity and can cause damage to, or even eradicate native species which natural cycles and other organisms depend on. While disrupting energy flow, food chains, and shaking the structure of ecosystems to the core, invasive species create not only ecological, but also a whole host of social, economic, and health issues that affect the livelihood of almost every organism on earth, including humans (CBD, 2009).
Invasive species, (also known as invasive alien species or simply alien species) are defined as any organism (plant, animal, pathogen, or other living thing) that is alien (non-native) to an ecosystem, which can cause adverse economical, ecological, or health effects to native species and/or humans. The roots of these problems all stem from the massive negative ecological impact these organisms are having on the environment (CBD, 2009). For all animal extinctions where the cause is known since the 1600’s, invasive alien species have been a contributing factor 40% of the time (CBD, 2006); the second most contributing factor to extinctions after loss of habitat (GC, 2013). By eliminating native species through competition for resources, predation, and transmittal of disease, invasive species continue to reduce biodiversity in almost all ecosystems around the world (CBD, 2009). In the future, this problem may worsen, and if no action is taken, could lead to a cascading ecological problem so large that whole communities or even ecosystems could collapse.
For example, one of Canada’s most prominent invasive species is the Zebra Mussel. These mussels grow on almost any hard surface such as boats, rocks or even on the shells of native clam species. This makes feeding difficult, and thus leads to deaths of the native species (GC, 2013). Another destructive invasive species in Canada are Japanese Knotweeds. These Asian shrubs grow in disturbed areas or along the banks of rivers or streams, and once settled, displace almost all native vegetation (GC, 2013). Many other Invasive species exist in Canada and around the world, but in Canada, the Zebra Mussel and Japanese Knotweeds are the most ruinous.
Invasive alien species are non-native to an area and therefore have either extended into areas outside their natural habitat, were intentionally introduced to an area, or were spread unknowingly by humans (GO, 2012). Each species is different and may be spread in a different way from the next. Some species even originate as counter measures to control other pests, which then proceed to take over the place of existing species (NRC, 2014). Certain conditions make some areas more susceptible to invasive intruders than others (Shelton, 2011).
Some of the ways in which invasive species are introduced include: shipping containers and vessels, boating (both recreational and...