Endangered Species
Essay by review • February 27, 2011 • Research Paper • 4,763 Words (20 Pages) • 3,157 Views
Currently in Canada, there are 543 species at risk with another 13 species already extinct. Extinction is caused by habitat destruction, invasive species, pollution, and overexploitation (1). In 1997, a committee was established whose responsibility was to evaluate the status of wildlife at risk in Canada. This committee, called the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), divides the endangered species in Canada into five categories. The first category includes species that are extinct, which means that they no longer exist anywhere in the world. The second category is extirpated species, which are species that no longer exist in Canada. The third is endangered species, which is a species that is facing imminent extinction or extirpation. The fourth grouping is threatened species, which are likely to become endangered if no immediate action is taken to conserve them. The last category is species of special concern, which are species at risk of becoming threatened or extinct because of biological characteristics or identified threats (2). These categories are useful because they bring attention to which species need urgent protection and which species should be monitored in order to avoid becoming endangered or threatened. The categories also help in forming the legislation that protects Canadian wildlife and habitat. On June 5, 2003, the Species at Risk Act (SARA) was created by COSEWIC in order to protect our endangered species and their habitats (3). COSEWIC also makes recommendations to the federal government about which species should be considered for listing as well as status updates on listed species.
Although there are many efforts to conserve our endangered species through government legislation and non-profit organizations, there is only a small improvement in the current situation of Canada's wildlife. There are also many causes for these species becoming at risk but the most prominent is that of habitat destruction by human activities. Therefore, humans are largely responsible for the endangerment of wildlife through habitat destruction or disruption, and the efforts being taken by the government are unsatisfactory.
Each year COSEWIC does an assessment of the current species populations in Canada in order to examine the areas of concern. The following table is from the most recent assessment held at the end of November 2007 (4)
Summary of COSEWIC assessment results as of November 2007: risk status according to taxonomic group*
Status / Statut Mammals /
Mammifиres Birds /
Oiseaux Reptiles /
Reptiles Amphibians /
Amphibiens Fishes /
Poissons Arthropods /
Arthropodes Molluscs /
Mollusques Vascular Plants /
Plantes vasculaires Mosses /
Mousses Lichens /
Lichens Total / Totaux
Extinct/
Disparue 2 3 0 0 6 0 1 0 1 0 13
Extirpated/
Disparue du pays 3 2 4 1 4 3 2 2 1 0 22
Endangered/
En voie de disparition 21 27 12 7 34 15 16 84 7 2 225
Threatened/
Menacйe 17 16 14 5 26 6 3 50 3 1 141
Special Concern/
Prйoccupante 26 23 8 7 41 4 4 32 4 6 155
Total / Totaux 69 71 38 20 111 28 26 168 16 9 556
*Species in at-risk categories include those designated as Extirpated, Endangered, Threatened, or Special Concern
30/11/2007
How a Species Becomes At Risk
There are a number of reasons as to why a species can become at risk. These include, but are not limited to, habitat loss, genetic and reproductive isolation, environmental contamination, suppression of natural events, hunting, excessive trade, climate change, disease, and invasive species.
Habitat loss is the largest problem Canadian species face. In fact, "60 percent of species that the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) identified as being at risk are affected by habitat problems" (5). The human population is expanding and has been taking over increasing amounts of land each year. Whether humans build on forest land, participate in logging, or manipulate water through the use of dams, they are destroying or disrupting the habitat of our wildlife in Canada.
Genetic and reproductive isolation play a role in putting species at risk as well. When a species' habitat becomes destroyed or fragmented, some species in a population may become geographically isolated from the rest of that population. The isolation causes the population's genetic variability to decrease and consequently the species becomes more susceptible to disease and death through natural selection.
Contamination is another way humans destroy natural habitats of Canadian wildlife. It is most commonly caused by chemicals being sprayed onto vegetation, but can also result from emissions into the air or water. These emissions can have a direct impact on our wildlife or can affect them indirectly, for example, by depleting the ozone layer.
As well as putting species at risk by destroying their habitat, humans are also at fault for suppressing natural events such as forest fires and flooding. These fires are essential to provide wildlife with the barren patches some species need to live in, while the floods replenish the small ponds that many species call home. When humans prevent or decrease these natural events, they are destroying the balance of nature.
Hunting and excessive trade play a large role in putting species at risk because these actions greatly reduce the population size. When a species is hunted for food, or its pelt, that species population is being depleted because of the excessive amount of hunting being done. Excessive trade happens when a species is traded because of its health benefits, used as a hunting trophy, or taken from its environment to become a pet. This also causes population depletion within a species.
Climate change, disease, and invasive species are the last three elements that are involved in putting species at risk. Whether the climate change is natural or human induced, it
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