Ocean predation and mortality of adult Atlantic salmon

Published version, available at: https://doi.org/10.1038/s41598-019-44041-5 Predation and mortality are often difficult to estimate in the ocean, which hampers the management and conservation of marine fishes. We used data from pop-up satellite archival tags to investigate the ocean predation and mo...

Full description

Bibliographic Details
Published in:Scientific Reports
Main Authors: Strøm, John Fredrik, Rikardsen, Audun Håvard, Campana, Steven E., Righton, David, Carr, Jonathan, Aarestrup, Kim, Stokesbury, Michael J.W., Gargan, Patrick, Javierre, Pablo Caballero, Thorstad, Eva Bonsak
Format: Article in Journal/Newspaper
Language:English
Published: NatureResearch 2019
Subjects:
VDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497
VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480::Marinbiologi: 497
Canada
Norway
Atlantic salmon
North Atlantic
Salmo salar
toothed whales
Online Access:https://hdl.handle.net/10037/15762
https://doi.org/10.1038/s41598-019-44041-5
Description
Summary:Published version, available at: https://doi.org/10.1038/s41598-019-44041-5 Predation and mortality are often difficult to estimate in the ocean, which hampers the management and conservation of marine fishes. We used data from pop-up satellite archival tags to investigate the ocean predation and mortality of adult Atlantic salmon (Salmo salar) released from 12 rivers flowing into the North Atlantic Ocean. Data from 156 tagged fish revealed 22 definite predation events (14%) and 38 undetermined mortalities (24%). Endothermic fish were the most common predators (n = 13), with most of these predation events occurring in the Gulf of St. Lawrence and from the Bay of Biscay to the Irish Shelf. Predation by marine mammals, most likely large deep-diving toothed whales (n = 5), and large ectothermic fish (n = 4) were less frequent. Both the estimated predation rates (Zp) and total mortality rates (ZM) where higher for Atlantic salmon from Canada, Ireland, and Spain (Zp = 0.60– 1.32 y−1, ZM = 1.73–3.08 y−1) than from Denmark and Norway (Zp = 0–0.13 y−1, ZM = 0.19–1.03 y−1). This geographical variation in ocean mortality correlates with ongoing population declines, which are more profound for southern populations, indicating that low ocean survival of adults may act as an additional stressor to already vulnerable populations.

Similar Items