Effect of Sea-Age on the Reproductive Potential of Atlantic Salmon ( Salmo salar ) in Eastern Canada

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Author: Randall, R. G.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1989
• Subjects: Aquatic Science; Ecology, Evolution, Behavior and Systematics; Canada; Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1139/f89-272; http://www.nrcresearchpress.com/doi/pdf/10.1139/f89-272

Reproductive potential of Atlantic salmon (Salmo salar), defined as average eggs per fish in the spawning run, varied three-fold both within stocks over time and among stocks from different geographic areas. Eggs per spawner is a function of fecundity, sea-age, proportion of females, and female size; the latter three traits varied significantly among years for salmon in both the Miramichi and Restigouche Rivers, New Brunswick. Because all of the above traits are related to sea-age at maturity, eggs per spawner was significantly correlated with mean sea-age in both rivers (R 2 = 0.88 and 0.61, respectively). Among 10 different populations in eastern Canada, reproductive potential was also correlated with sea-age; for mean sea-ages (MSA) ranging from 1.0 to 1.8 yr, reproductive potential (RP) was defined by the power regression: RP = 1831.26 MSA 1.30 (R 2 = 0.64 P < 0.05). Thus reproductive potential can be estimated for any population for which the sea-age composition of spawners is known. Assuming a target egg deposition rate of 2.4 × 10 4 eggs per hectare, required spawners varied inversely with reproductive potential among the 10 populations, from five spawners (MSA = 1.75 yr) to 16 spawners (MSA = 1.15 yr) per hectare.