|Upstream movement by nonnative brook trout (Salvelinus fontinalis) promotes invasion of native cutthroat trout (Oncorhynchus clarki) habitat|
Peterson, D.P.; Fausch, K.D. (2003). Upstream movement by nonnative brook trout (Salvelinus fontinalis) promotes invasion of native cutthroat trout (Oncorhynchus clarki) habitat. Can. J. Fish. Aquat. Sci. 60(12): 1502-1516
In: Canadian Journal of Fisheries and Aquatic Sciences = Journal canadien des sciences halieutiques et aquatiques. National Research Council Canada: Ottawa. ISSN 0706-652X, more
Freshwater fish; Introduced species; Marine fish; Oncorhynchus clarkii (Richardson, 1836) [WoRMS]; Salvelinus fontinalis (Mitchill, 1814) [WoRMS]; Marine; Brackish water; Fresh water
|Authors|| || Top |
- Peterson, D.P.
- Fausch, K.D.
To understand how immigration and emigration influence the processes by which invading nonnative brook trout (Salvelinus fontinalis) displace native cutthroat trout (Oncorhynchus clarki), we studied trout movement in long segments of three mountain streams in Colorado during 1999-2001. Over 3500 trout were captured and marked at weirs and during electrofishing, both within and downstream of stream segments. Nearly 80% of brook trout captured at weirs were moving upstream, whereas almost 65% of cutthroat trout were moving downstream. Brook trout movements peaked in early summer and again in fall. Brook trout immigration rates from downstream source populations were high, and in one stream, invaders repopulated a segment where they were removed within 8 months. Immigrant brook trout were typically mature adults in similar body condition to the general population. Brook trout immigrated from a range of distances, with local movement within 250 m more frequently detected, but fish also moved from many distances up to 2 km away within a summer. Brook trout encroachment and invasion was characterized by a wave of local movement exerting biotic pressure on the downstream limit of the cutthroat trout population and jump dispersers moving upstream beyond the invasion front promoting rapid population spread.