The observed differences in run timing among populations were related to population size and sea-age group structure of the spawning stock, but not to in-river migration distances.
When humidity and grief choked the Mainland feeder towns of Linwood, Northfield and Somers Point, Khoury made the high school track part of his morning run, timing it to the football team's early workout.
We examined run timing of 1SW Atlantic salmon originating from multiple, genetically distinct populations within a single large river system.
Fisheries are opened conservatively based on predicted run timing to ensure that escapement goals are met; after that, fisheries are opened to a greater extent.
Despite the essential role of spawning migration in the life-cycle of Atlantic salmon, very few studies have investigated population-specific differences in run timing apart from distinguishing variation between sea-age groups.
However, our results highlight the importance of appropriate management units, since general trends, as e.g. 1SW females arriving earlier than males, may be driven by population rather than sex-specific differences in run timing.
Owing to its size selectivity and temporally variable nature (Ricker 1995; Quinn et al. 2007), commercial fishing in salmonids has been shown to impact several life-history traits such as growth, age and size at maturation, and run timing.
For comparing run timing among groups we used Wilcoxon rank scores [i.e. Mann–Whitney Wilcoxon test for two-sample data and Kruskal Wallis (K W) test in one-way ANOVA statistic].
Similarly, river flow regime affects run timing for both adults and out-migrating smolts (Quinn 2005) and recent research has revealed that patterns and the form of precipitation (i.e., rainfall versus snowfall) are changing as well (Stewart et al. 2005; Mote 2006).
One potential mechanism of selection for the earlier run timing of tributary 1SW salmon compared to the MS/HW is the water level and the accessibility of the spawning site.
