Habitat Loss and Westslope Cutthroat Trout

Habitat loss and degradation is often cited as a major impact and limiting factor for fish populations (e.g., native trout recovery plans). This stressor-response curve is exclusively meant to capture direct habitat loss. Direct habitat loss is defined as the removal of portions of a natural stream, or replacement of portions of a natural stream with a different landscape feature. For example, strip-mining for coal in parts of the native trout range has deleted some stream sections, or has resulted in the replacement of streams sections with open-pit lakes or with channeled stream analogs (i.e., a ditch) that do not provide trout habitat. The stressor-response curve for habitat loss is depicted by a linear relationship between the percentage of stream habitat lost and system capacity (Figure 1).