|Document Type:||Journal Article|
|Title:||Distribution, density, and size of migratory and fluvial sculpins in relation to barriers in Puget Sound lowland streams|
|Author:||Roger A. Tabor, Frithiof T. Waterstrat, Daniel W. Lantz, Hans B. Berge, Martin Liermann|
|Journal:||North American Journal of Fisheries Management|
We examined the effects of barriers on populations of migratory (Coastrange Sculpin C. aleuticus and Prickly Sculpin C. asper) and non-migratory sculpin (Riffle Sculpin C. gulosus, Shorthead Sculpin C. confusus, and Torrent Sculpin C. rhotheus). Because migratory sculpin have pelagic larvae that drift downstream to calm waters and juveniles and adults migrate upstream, barriers can alter their distribution. We compared sculpin populations upstream and downstream of barriers in 19 Puget Sound, Washington lowland streams. All streams had populations of Coastrange Sculpin or Prickly Sculpin or both in stream reaches downstream of the barrier. In 8 of the 19 streams studied, at least one species of non-migratory sculpin was also present. Non-migratory sculpin can complete their life cycle in a relatively small area and barriers are less likely to affect their distribution but they may be indirectly affected by barriers through interactions with migratory sculpin. In all streams examined, the density of migratory sculpin immediately upstream of the barrier was lower than immediately downstream of the barrier. In 12 of the 19 streams, migratory sculpin were not present immediately upstream of the barrier. The few migratory sculpin collected upstream of the barrier were considerably larger than those collected downstream of the barrier. In most streams with non-migratory sculpin populations, non-migratory sculpin were rare downstream of the barrier and abundant upstream of the barrier. We also documented the longitudinal distribution of sculpin in one stream without a barrier. Migratory sculpin species dominated the lower stream reaches and were gradually replaced by non-migratory sculpin species in more upstream reaches. The abundance of migratory sculpin appears to be largely constrained by their ability to migrate upstream, whereas the abundance of non-migratory sculpin is likely influenced by interactions with migratory sculpin species. Overall, barriers appear to have a strong effect on the distribution of migratory sculpin and indirectly on the distribution non-migratory sculpin and need to be taken into account when assessing fish communities in Puget Sound lowland streams.
|Theme:||Habitats to Support Sustainable Fisheries and Recovered Populations|
Characterize relationships between habitat and ecosystem processes, climate variation, and the viability of organisms.