Publication Abstract

Emergenceof Atlantic salmon, Salmo salar L., fry in a chalk stream

W. D. Riley and A. Moore

The emergence ofAtlantic salmon, Salmo salar L., fry from spawning gravels occurs principally atnight. Nocturnal emergence of fry is also evident in other salmonid species and has beendemonstrated both in artificial redds within the laboratory, and in the wild. A number oftheories have been proposed to explain the mechanisms controlling this pattern ofemergence. For instance, suggested that the sharp diel periodicity in Atlantic salmon wasdue either to a stimulus-response or a clock-controlled mechanism, and that thesynchronous nocturnal emergence was probably a predator avoidance tactic. However,suggested that stream flow had a strong influence on the emergence of chinook salmon, Oncorhynchustshawytscha, (Walbaum) fry. The present study describes the use of emergence traps toinvestigate the possible environmental cues triggering the emergence of wild Atlanticsalmon fry from redds in a chalk stream.

Reference:

W. D. Riley and A. Moore, 2000. Emergence of Atlantic salmon, Salmo salar L., fryin a chalk stream. Fisheries Management and Ecology, 7(5): 465-468.