Northwest Fisheries Science Center

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Document Type: Journal Article
Center: NWFSC
Document ID: 4267
Title: Abundance and body condition of sculpin (Cottids spp.) in a small forest stream following recolonization by juvenile coho salmon Oncorhynchus kisutch
Author: Sean M. Naman, Peter M. Kiffney, G. R. Pess, T. W. Buehrens, T. R. Bennett
Publication Year: 2013
Journal: River Research and Applications
Volume: 20
Issue: 3
Pages: 360-371
Keywords: sculpin, Pacific salmon, recolonization, streams,
Abstract:

Recolonization by native species following reintroduction can affect resident species through a variety of processes. We examined the effects of natural recolonization by coho salmon Oncorhynchus kisutch on sculpin (Cottus rhotus and C. gulosus), a small benthic fish, in a small forest stream in Western Washington, USA. Provision of fish passage around a small dam allowed coho access to habitat which had been inaccessible for over 100 years. We found that density (g m-2 and number m-2) was unchanged and body condition (the slope of the relationship between length and weight) of sculpin tended to increase from before relative to a five year period following recolonization. The proportion of sculpin comprising the total fish assemblage decreased after coho colonization relative to before but remained stable for a five year period after coho reintroduction while coho density increased over five fold. Additionally, we used Akaikes Information Criteria to evaluate the relative importance of physical and biological variables in predicting sculpin density in pool habitats during the initial coho recolonization period. Physical microhabitat variables had little support for predicting sculpin density, while there was significant support for stream temperature; cutthroat trout (O. clarki) density and year as predictors of sculpin density. Coho density was not significant in any model. Our results indicate coho introduction and subsequent recolonization has had minimal individual or population level effects on sculpin therefore demonstrating that species reintroductions into portions of their native range can have no measurable effect on resident organisms.

URL1: The next link will exit from NWFSC web site http://dx.doi.org/10.1002/rra.2643
Notes: DOI: 10.1002/rra.2643
Theme: Recovery, Rebuilding and Sustainability of Marine and Anadromous Species
Foci: Develop methods to use physiological and biological information to predict population-level processes.