Fragmentation of juvenile salmon habitat by road and forest culverts

An analysis of 123 culverts on Cascapédia, Matapédia, Patapédia and Ste-Marguerite rivers show that only 36% are classified impassable barriers when Coffman filter (2005) developed for juvenile salmonids is used. Although this filter is the best available tool, it was not developed for salmon. This result however is of sufficient concern to justify developing such a filter specific to juvenile salmon. During the course of this project, we will use passive transponder technology to complete a study of marking-recapturing on a large number of culverts of variable features. With this study we will identify their variables and thresholds limiting the passage of juveniles. Then this filter will be applied to all salmon river culverts to determine to what degree they are passable. A GIS analysis will allow for the calculation of loss of habitats in relation to each culvert classified as impassable.

Contact: Normand Bergeron, 418-654-3703, normand.bergeron@ete.inrs.ca