Why is the Banff Springs Snail Endangered?

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) is responsible for determining the national status of Canada’s plants and animals. When the federal government passed the Species at Risk Act (SARA) in the summer of 2002, the mandate of COSEWIC was legally established. COSEWIC uses the best available scientific as well as Aboriginal and Community Knowledge to assess the probability of Canada’s native birds, mammals, reptiles, amphibians, fishes, arthropods, vascular plants, mosses, lichens and molluscs of going extinct – disappearing forever from the earth – or being extirpated – disappearing from the wild in Canada.

COSEWIC uses five quantitative criteria to assess the status of the species as presented in a written status report:

A. Decline in Total Number of Mature Individuals
B. Small Distribution Range and Decline or Fluctuation
C. Small and Declining Number of Mature Individuals
D. Very Small or Restricted Total Population
E. Quantitative Analysis

Status can range from extinct to not at risk.

When COSEWIC first examined the Banff Springs Snail in 1997, they determined that the species was Threatened. At that time, Threatened meant that it was a species likely to become endangered if limiting factors were not reversed. Also at that time, it was the first living mollusc to be assessed in Canada by COSEWIC.

In May 2000, COSEWIC adopted quantitative criteria more similar to that used by the IUCN (International Union for the Conservation of Nature) and re-examined the status of the Banff Spring Snail. They uplisted the Banff Springs Snail to Endangered – a species facing imminent extirpation or extinction. The reason for designation was that it was a “Highly specialized species with extremely limited distribution subject to human disturbance and extreme fluctuations in population size.”

When SARA passed in 2002, many of the animals and plants that were assessed by COSEWIC as being Extirpated, Endangered, Threatened, and Special Concern, including the Endangered Banff Springs Snail, were automatically listed and legally protected under SARA.

According to SARA, COSEWIC must re-assess each species once every 10 years. In 2008, the status of Endangered was confirmed by COSEWIC.

The Banff Springs Snail is endangered because it meets the following quantitative criteria: B1ac(iv)+2ac(iv). The official reason for designation is as follows:


Details on COSEWIC and the criteria they use can be found at http://www.cosewic.gc.ca. Status reports and other documents on the recovery of species can be found at http://www.sararegistry.gc.ca.

Next Page – Why do the Populations of the Banff Springs Snail Fluctuate?