Reduction in growth due to electrofishing and tagging may change interannual movement behavior of stream salmonids: Evidence from Arctic grayling in an interior Alaskan stream

Authors
Citation
Nf. Hughes, Reduction in growth due to electrofishing and tagging may change interannual movement behavior of stream salmonids: Evidence from Arctic grayling in an interior Alaskan stream, T AM FISH S, 127(6), 1998, pp. 1072-1077
Citations number
30
Categorie Soggetti
Aquatic Sciences
Journal title
TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY
ISSN journal
00028487 → ACNP
Volume
127
Issue
6
Year of publication
1998
Pages
1072 - 1077
Database
ISI
SICI code
0002-8487(199811)127:6<1072:RIGDTE>2.0.ZU;2-O
Abstract
I show that the growth rate of Arctic grayling Thymallus arcticus is reduce d by electrofishing and tagging (Floy FD-67 internal anchor tags) and prese nt evidence that this reduction may alter interannual movement behavior. I demonstrate the reduction in growth by comparing length at age and annual g rowth of fish that either were or were not electrofished and tagged 1 year previously. For six of the seven ages compared (ages 3-9), the mean length of electrofished and tagged fish was reduced; in four cases the reduction w as significant (P < 0.05 or P < 0.001). Annual growth of electrofished and tagged fish was also significantly less than that of untagged fish (P < 0.0 001), with a median reduction of 18%. These reductions in growth may change a fish's movement behavior because fish that move upstream grow more quick ly than fish that stay put or move downstream. If differences in growth are responsible for differences in movement, the effects of electrofishing and tagging are large enough to turn a fish destined to move upstream into one that stays put or moves downstream.