Spawning and movement behavior of migratory coastal cutthroat trout on the western Copper River delta, Alaska.

Abstract

We studied the movement patterns of migratory coastal cutthroat trout Oncorhynchus clarkii clarkii in the western Copper River delta, Alaska, near the northern extent of the subspecies' distribution. Life history information for coastal cutthroat trout is scarce within this region. Movement of coastal cutthroat trout was monitored from 1994 to 1996 with radiotelemetry and tag-recapture of fish at a two-way fish weir. Radiotracking of 20 adults was conducted for a period ranging from 5 to 343 d. We observed anadromous and potamodromous migrations by fish that were morphologically indistinguishable and spanned a similar size range (mean fork length = 364 mm). Within these migratory groups, fish exhibited variation in movement patterns, including the timing of entry to spawning streams and postspawning movements. Anadromous and potamodromous fish entered study streams either during fall to overwinter and then spawn or during the spring just before spawning. Spawning was most concentrated in the upper portions of the study streams and occurred upstream to the highest available areas. Postspawning movements of potamodromous fish consisted of small-scale (

Citation

Saiget, D.A.; Sloat, M.R.; Reeves. G.H. 2007. Spawning and movement behavior of migratory coastal cutthroat trout on the western Copper River delta, Alaska. North American Journal of Fisheries Management. 27: 1029-1040