Emergence, population densities, and growth of salmon and trout fry in two New Brunswick streams

• Published in: Canadian Journal of Zoology
• Main Author: Randall, Robert G.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1982
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1139/z82-288; http://www.nrcresearchpress.com/doi/pdf/10.1139/z82-288

Postemergent downstream dispersal of Atlantic salmon fry (Salmo salar) was monitored using drift samplers during spring 1978 in two Miramichi River, N.B., tributaries. Catch rates of salmon fry peaked during the 2nd and 3rd weeks of June in both streams, coinciding with peak emergence of the salmon from the gravel. Very few trout fry (Salvelinus fontinalis) were captured in the drift nets, but electrofishing results indicated trout emergence preceded salmon by about 3 weeks.The earlier emergence of the trout gave them an early growth advantage over the salmon, so that trout fry were usually larger than salmon fry inhabiting the same stream areas. Early growth rates of both salmon and trout were quite varied among four stream sites during 2 years when growth was monitored; growth differences were discussed in relation to stream temperatures and density-dependent growth. Salmon fry were more abundant than trout fry at most sites in both years.