Skip booklet index and go to page content

COSEWIC Assessment and Update Status Report on the Deepwater Sculpin (Western and Great Lakes-Western St. Lawrence Populations) in Canada

Special Significance of the Species

In lakes where it is present, the deepwater sculpin’s ecological role as a major prey item of economically important piscivores such as lake trout and burbot cannot be over-emphasized (Day 1983).

In the Great Lakes, the species is an excellent indicator of the well-being of the deepwater fish community and habitat. Its 1996 reappearance in Lake Ontario signalled a series of changes in the open-water fish community (Casselman and Scott 2003, Mills et al. 2003) and a possible reduction in the predatory effects of smelt, alewife, and burbot. It is also thought to be negatively affected by contaminants, possibly of the deepwater habitat. However, this is only speculation. Its reappearance in Lake Ontario, when it was thought to be extirpated, was particularly encouraging, possibly signalling that Lake Ontario was, in a number of ways, recovering from a more degraded fish community and habitat seen through much of the last half-century.

Finally, deepwater sculpins are of special concern to those interested in zoogeography and post-glacial dispersal within Canada (Scott and Crossman 1973).