Evol Ecol Res 17: 95-109 (2016)     Full PDF if your library subscribes.

Fine-scale life-history structure in a highly mobile marine fish

Nancy E. Roney1, Jeffrey A. Hutchings1,2,3, Esben Moland Olsen2,3,4, Halvor Knutsen2,3,4, Jon Albretsen4 and Anna Kuparinen5

1Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada,  2Centre for Ecological and Evolutionary Synthesis (CEES), Department of Bioscience, University of Oslo, Oslo, Norway,  3Department of Natural Sciences, Faculty of Engineering and Science, University of Agder, Kristiansand, Norway,  4Institute of Marine Research, Flødevigen Marine Research Station, His, Norway and  5Department of Environmental Sciences, University of Helsinki, Helsinki, Finland

Correspondence: N.E. Roney, Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
e-mail: neroney@gmail.com


Background: A highly mobile marine fish, Atlantic cod (Gadus morhua), inhabits southern Norwegian coastal habitats that offer limited potential for individual dispersal and migration.

Questions: Do coastal populations of cod differ in life history? If so, is the variability spatially persistent and does it vary with time? What factors are responsible for life-history differences among the potential populations?

Method: Use long-term, fisheries-independent survey data to measure and compare life-history metrics among nine regions along the southern Norwegian coast. Conduct maturity analyses, using generalized linear mixed-effect models, where the probability of being mature is a function of fixed effects (length, age, weight, sex, and growing degree days) and random effects (location and year class nested within location).

Results: We detected that the probability of being mature has increased spatially (along an increasing longitudinal cline) and temporally (throughout a 30-year time-series). Neither of these trends could be fully explained by variation in sea temperature or population density.

Conclusion: Life-history variability in a highly mobile marine fish can be evident, and temporally persistent, at spatial scales considerably smaller than those encompassed by established fisheries management units and species recovery strategies. Our findings provide empirically defensible justification for studies on the ecological factors and evolutionary mechanisms responsible for producing and maintaining this variability.

Keywords: Gadus morhua, life history, maturity, Skagerrak, small-scale.

IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.


        © 2016 Nancy E. Roney. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.

       Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.

       All copies of abstracts and articles must preserve their copyright notice without modification.