0000000000297589

AUTHOR

Olav Sigurd Kjesbu

showing 3 related works from this author

Ecosystem processes are rarely included in tactical fisheries management

2015

Fish stock productivity, and thereby sensitivity to harvesting, depends on physical (e.g. ocean climate) and biological (e.g. prey availability, competition and predation) processes in the ecosystem. The combined impacts of such ecosystem processes and fisheries have lead to stock collapses across the world. While traditional fisheries management focuses on harvest rates and stock biomass, incorporating the impacts of such ecosystem processes are one of the main pillars of the ecosystem approach to fisheries management (EAFM). Although EAFM has been formally adopted widely since the 1990s, little is currently known to what extent ecosystem drivers of fish stock productivity are actually imp…

0106 biological sciencesEcosystem healthbusiness.industry010604 marine biology & hydrobiologyEnvironmental resource managementManagement Monitoring Policy and LawAquatic ScienceOceanographyFish stock010603 evolutionary biology01 natural sciencesEcosystem valuationEcosystem-based managementEcosystem servicesEcosystem managementEcosystem14. Life underwaterFisheries managementbusinessEcology Evolution Behavior and SystematicsFish and Fisheries
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Oogenesis and reproductive investment of Atlantic herring are functions of not only present but long-ago environmental influences as well

2017

Following general life history theory, immediate reproductive investment (egg mass × fecundity/body mass) in oviparous teleosts is a consequence of both present and past environmental influences. This clarification questions the frequent use of season-independent (general) fecundity formulas in marine fish recruitment studies based on body metrics only. Here we test the underlying assumption of no lag effect on gametogenesis in the planktivorous, determinate-fecundity Atlantic herring (Clupea harengus) displaying large plasticity in egg mass and fecundity, examining Norwegian summer–autumn spawning herring (NASH), North Sea autumn-spawning herring (NSAH), and Norwegian spring-spawning herri…

0106 biological sciences010603 evolutionary biology01 natural sciencesZooplanktonZooplanktonLife history theoryOogenesisHerringAnimalsAtlantic herringLarvaMultidisciplinarybiologyNorwayEcologyReproduction010604 marine biology & hydrobiologyFishesClupeaBiological Sciencesbiology.organism_classificationFecundityFertilitySeafoodLarvaOocytesNorth SeaOviparityProceedings of the National Academy of Sciences
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Genomic stability through time despite decades of exploitation in cod on both sides of the Atlantic

2021

Significance Both theory and experiments suggest that fishing can drive the evolution of an earlier maturation age. However, determining whether changes in the wild are the result of fisheries-induced evolution has been difficult. Temporal, genome-wide datasets can directly reveal responses to selection. Here, we investigate the genomes of two wild Atlantic cod populations from samples that pre- and postdate periods of intensive fishing. Although phenotypic changes suggest fisheries-induced evolution, we do not find evidence for any strong genomic change or loss of genetic diversity. While evolution could have occurred through undetectable frequency changes at many loci, the irreversible lo…

0106 biological sciences0301 basic medicinepopulation genomicsFishing430010603 evolutionary biology01 natural sciencesGenomeGenomic InstabilityPopulation genomicsEvolution Molecular03 medical and health sciencesselective sweepsEffective population sizeGadusAnimalsBiomassAtlantic OceanGenetic diversityMultidisciplinaryPolymorphism GeneticbiologyPopulation Biologyfisheries-induced evolutiongenetic diversityBiological Sciencesbiology.organism_classification030104 developmental biologyArcticGadus morhuaEvolutionary biologysense organsAtlantic codhistorical DNA
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