title: Stock-specific variation of trophic position, diet and environmental stress markers in Atlantic salmon Salmo salar during feeding migrations in the Baltic Sea.
abstract: This study investigated stock-specific variation in selected ecophysiological variables during the feeding migrations of Atlantic salmon Salmo salar in the Baltic Sea. Oxidative stress biomarkers and EROD (ethoxyresorufin-O-deethylase, Cyp1A enzyme) activity were used as indicators of possible environmental stress and stable isotopes as determinants of diet and trophic position. Latvian S. salar stocks Daugava and Gauja had distinct stable-isotope signatures compared to the other stocks, indicating differences in migration patterns, residency or arrival times, or dietary specialization among stocks. Salmo salar originating from Daugava and Gauja also had lower catalase enzyme activity than the other stocks. Post-smolts originating from rivers of the Gulf of Finland had elevated EROD activities compared to fish of the same age from Bothnian Bay rivers, which could indicate exposure to organochlorine pollutants. No other stock-specific differences in oxidative stress biomarkers were found. The study demonstrates how genetic, oxidative stress biomarker, EROD and stable-isotope data may be combined to study trophic position, prey prevalence and environmental stress of mixed S. salar stocks foraging in the sea.
authors.affiliation: Centre of Excellence in Evolutionary Genetics and Physiology, Department of Biology, University of Turku, Turku, Finland. kranvu@utu.fi
authors.forename: K
authors.initials: K
authors.lastname: Vuori
authors.forename: M
authors.initials: M
authors.lastname: Kiljunen
authors.forename: M
authors.initials: M
authors.lastname: Kanerva
authors.forename: M-L
authors.initials: ML
authors.lastname: Koljonen
authors.forename: M
authors.initials: M
authors.lastname: Nikinmaa
mesh_terms: D025041:Animal Migration; D000818:Animals; D015415:Biomarkers / Q000032:analysis*; D002247:Carbon Isotopes / Q000032:analysis; D019363:Cytochrome P-450 CYP1A1 / Q000032:analysis; D004032:Diet; D004777:Environment; D005260:Female; D005978:Glutathione / Q000032:analysis; D015227:Lipid Peroxidation; D008297:Male; D018895:Microsatellite Repeats; D009587:Nitrogen Isotopes / Q000032:analysis; D018384:Oxidative Stress; D020317:Salmo salar / Q000235:genetics / Q000502:physiology*; D017422:Sequence Analysis, DNA
chemical_list: D015415:Biomarkers; D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D019363:Cytochrome P-450 CYP1A1; D005978:Glutathione