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Atlantic salmon (Salmo salar) populations throughout the North Atlantic have declined in recent decades largely due to reduced marine survival, yet our understanding of marine distribution patterns and migratory routes remains limited. Here, we assigned archived individual samples (n  =   3891) collected over a half century (1968–2018) throughout the North Atlantic to region of origin using range-wide genetic assignment. In the Northwest Atlantic, the distribution of assignments reinforced the importance of the Labrador Sea as an aggregation area, with 73% of all reporting groups detected. Moreover, individuals from six European reporting groups were identified in the Northwest Atlantic, and detections decreased with decreasing latitude spanning an area from Greenland to southern Newfoundland. In the Northeast Atlantic, six North American reporting groups were detected in samples from around the Faroe Islands. Based on the distribution of samples, estimates of trans-Atlantic migration distance averaged 3861 and 2889 km for North American and European salmon respectively. Our analysis highlights the widespread importance of the Labrador Sea and Faroe Islands to the species marine distribution patterns, and the prevalence of long-distance trans-Atlantic migration. Ultimately, the results suggest that environmental conditions experienced by many Atlantic salmon populations span much of the North Atlantic Ocean. [ABSTRACT FROM AUTHOR]

Marine exploitation rates were estimated for nine Newfoundland Atlantic salmon (Salmo salar L.) populations, separately for small and large salmon size components. Estimates were derived using counts of salmon returning to fish counting facilities rather than from tagging studies and thus adjustments were not required to account for tag loss, handling or tagging mortality, or tag reporting rates. For all stocks combined, the overall marine exploitation rate during the period 1984–1991 averaged 45.3% (29.6–57.1%) on small salmon and 74.2% (57.7–83.7%) on large salmon. These estimates are considered minimum values. Concerns related to declining salmon abundance resulted in the closure of the Newfoundland commercial salmon fishery in 1992. Results are discussed in relation to previous estimates derived from tagging, and highlight the importance of accounting for marine exploitation when examining trends in salmon survival and return data even when commercial fisheries have been closed. [ABSTRACT FROM PUBLISHER]

Five-thousand wild Atlantic salmon (Salmo salar L.) smolts from Conne River, Newfoundland, were captured during their downstream migration in May 1995, and transferred to an estuarine aquaculture rearing site at Roti Bay, 23 km away. Survival was monitored throughout the experiment. The greatest mortality occurred in July, approximately 6–8 weeks following transfer. Survival of smolts to one-sea-winter salmon was 18.5%, over four times higher than the average survival of wild salmon to Conne River during the past 6 years. Growth was monitored at monthly intervals until November 1995, with additional sampling in the spring and early summer of 1996. Survivors were split into two groups and released directly into the Bay d'Espoir fjord; one group was released 27–28 June 1996, at a site approximately 7 km from the mouth of Conne River. The second group was retained at Roti Bay and released 23 July 1996. Lotek radio transmitter tags were used in evaluating the success of the experiment by tracking migration timing and subsequent distribution of cage-reared salmon throughout the Conne River system. Approximately 80% returned to Conne River and 20% strayed to other streams. Less than 50% of the surviving fish were later accounted for in local Bay d'Espoir rivers. Results are discussed in relation to the utility of this technique to enhance salmon populations. [ABSTRACT FROM PUBLISHER]

A management plan was introduced in 1984 to rebuild depressed Atlantic salmon (Salmo salar L.) stocks in mainland Canada and southwestern Newfoundland. The focus of the plan was a reduction in the interception and exploitation of large salmon, primarily virgin multi-sea-winter salmon, in the commercial fisheries of Newfoundland and Labrador. The plan was evaluated based on analyses of the timing of commercial catches, proportions of large salmon in commercial catches, and levels of catch. Analyses of the impacts of changes in the commercial fisheries in river escapements in Newfoundland and Labrador were based on changes in recreational catches and counts at fishways. With respect to commerical fisheries, the timing of catches of large salmon was later, and the percentages and levels of catches of this component tended to be lower in plan years (1984–1988) than in pre-plan years (1974–1983). However, declines in percentages and catches of large salmon began prior to the initiation of the plan in 1984. Timing and levels of catches of small salmon did not change appreciably in most areas. These results were consistent with plan objectives. While the delayed season appears to have achieved results consistent with plan expectations for large salmon, it is not possible to determine the contribution of reductions in licensed gear in this regard. Although not an objective of the plan, restrictions imposed in the commercial fisheries did not result in increased escapements of grilse in either Newfoundland (except for two areas) or Labrador. No changes in escapements and in catches suggests that the overall abundance of grilse did not change between pre-plan and plan years and that reductions in licensed effort had little effect on reducing commercial catches. No increases were noted for escapements of large salmon (except for one area). Overall observations pertaining to river escapements were not consistent with plan expectations. [ABSTRACT FROM PUBLISHER]