ORCID Profile
0000-0003-1572-5429
Current Organisations
University of Agder
,
University of Jyväskylä
,
Dalhousie University
,
Norwegian Institute of Marine Research
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Publisher: Oxford University Press (OUP)
Date: 16-10-2019
Abstract: Iteroparity is a bet-hedging strategy where in iduals spread the risk of reproductive failure over time. The occurrence of iteroparity (i.e. proportion of repeat spawners in annual returns) varies among Atlantic salmon (Salmo salar) populations, yet information on its ecological importance is limited. We compiled multi-decadal time series on the spawning history composition of Atlantic salmon annual returns across ten populations of the northwest Atlantic and West Greenland mixed-stock fishery landings to: (i) describe spatio-temporal patterns of iteroparity at the continental scale (ii) quantify the reproductive contributions of repeat spawners and (iii) test the hypothesis that iteroparity acts as a population safeguard during periods of low recruitment through repeat spawners’ contributions. Despite high variability in the representation of repeat spawners among populations and years (range: 0–24.7% average: 5.0%), we identified broad-scale spatio-temporal shifts in iteroparity, with increases in mid-latitudinal and northern populations (from 3.1% to 7.6%) and declines in southern areas (from 4.1% to 2.7%), between the 1971–1992 and 1993–2017 periods. Our findings highlight the potential for increased prevalence of iteroparity when threats are mitigated (e.g. fishing pressure), with measurable benefits to population processes manifested by the high reproductive contributions of repeat spawners, especially in years of low maiden spawner abundance.
Publisher: Informa UK Limited
Date: 02-07-2016
Publisher: Public Library of Science (PLoS)
Date: 19-05-2020
Publisher: Canadian Science Publishing
Date: 06-2010
DOI: 10.1139/Z10-033
Abstract: In many species, females are thought to base their choice of mate on quality, which males signal through displays and body ornamentation. One important question is whether these signals represent an honest reflection of quality so that they carry an intrinsic cost to the male. A considerable body of evidence has revealed complex mating behaviours in gadoid fish, such as Atlantic cod ( Gadus morhua L., 1758), for which male reproductive success may be related to some form of female choice. However, if present, the cost of male signalling is not clear. To test the hypothesis that male behavioural displays are energetically costly, we quantified the number of displays initiated by males during spawning, and their corresponding mass loss, in two separate experiments. The number of displays was positively associated with mass loss in both experiments, suggesting that reproductive displays are costly to males they also may be regarded as an honest signal of quality upon which females could base their choice of mate. To our knowledge, this is the first study to demonstrate a cost of male reproductive behaviour in a broadcast-spawning fish.
Publisher: Oxford University Press (OUP)
Date: 11-04-2011
Abstract: Skjæraasen, J. E., Meager, J. J., Karlsen, Ø., Hutchings, J. A., and Fernö, A. 2011. Extreme spawning-site fidelity in Atlantic cod. – ICES Journal of Marine Science, 68: 1472–1477. Based on a 3-year mark-recapture study, evidence is provided of spawning-site fidelity in Atlantic cod (Gadus morhua) at a scale ( km) smaller than documented previously. Coastal regions where barriers to dispersal exist may allow for local population dynamics and adaptation to develop in broadcast-spawning marine fish at extremely fine spatial scales.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 31-07-2009
Abstract: In the debate concerning the future of the world's fisheries, some have forecasted complete collapse but others have challenged this view. The protagonists in this debate have now joined forces to present a thorough quantitative review of current trends in world fisheries. Worm et al. (p. 578 ) evaluate the evidence for a global rebuilding of marine capture fisheries and their supporting ecosystems. Contrasting regions that have been managed for rebuilding with those that have not, reveals trajectories of decline and recovery from in idual stocks to species, communities, and large marine ecosystems. The management solutions that have been most successful for rebuilding fisheries and ecosystems, include both large- and small-scale fisheries around the world.
Publisher: Inter-Research Science Center
Date: 08-09-2016
DOI: 10.3354/MEPS11819
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Jeffrey Hutchings.