DOI: 10.5061/dryad.3n5tb2rht
title: Biological and growth data of wild and hatchery-reared sea trout (Salmo trutta L.) individuals

description: Each year, millions of hatchery-reared sea-run brown trout Salmo trutta L.
 (the sea trout) juveniles are released into the natural environment in the
 Atlantic region. The aim of this work was to investigate the growth
 responses of sea trout to changing temperature conditions and to compare
 the growth plasticity between wild and hatchery-reared fish. Scales were
 collected from sea trout in a selected river flowing into the southern
 Baltic Sea. We analyzed the scale increment widths as a proxy of somatic
 growth and investigated the interannual variabilities and differences in
 growth between fish groups (wild and hatchery-reared). We used
 mixed-effects Bayesian modeling and ascribed the variances in growth to
 different sources. Furthermore, we developed indices of interannual
 (2003–2015) growth variation in the marine and freshwater phases of the
 life cycle of the fish and analyzed the relationships between trout growth
 and temperature. Temperature positively affects fish growth, regardless of
 the origin of the fish. We observed stronger relationships between fish
 growth and temperature conditions in the marine phase than in the
 freshwater phase. Additionally, wild sea trout are characterized by
 stronger responses to temperature variability and higher phenotypic
 plasticity of growth than those of the hatchery-reared individuals.
 Therefore, wild sea trout might be better suited to changing environmental
 conditions than hatchery-reared sea trout. This knowledge identifies
 possible threats in management actions for sea trout with an emphasis on
 ongoing climate change.
description: The methods of the data collection are decribed in the paper
 published in Ecology and Evolution: Lejk A.M., Smoliński S., Ratke G.,
 Martyniak A. (2021). Higher growth variability and
 stronger responses to temperature changes in wild than hatchery-reared sea
 trout (<em>Salmo trutta</em>
 L.).
description: Capture_year - the year of sampling
 L_caudalis  - fish fork length (cm) Weight -
 fish body mass (g) Age_river - number of winters spent
 in the freshwater Age_sea - number of winters spent in
 the sea Increment_1_river - scale increment of 1st
 freshwater annual growth zone (accuracy ± 0.01 μm)
 N_1_river - number of circuli
 Increment_2_river - scale increment of 2nd freshwater annual
 growth zone (accuracy ± 0.01 μm) N_2_river - number of
 circuli Increment_3_river - scale increment of 3rd
 freshwater annual growth zone (accuracy ± 0.01 μm)
 N_3_river - number of circuli Increment_1_sea
 - scale increment of 1st marine annual growth zone (accuracy ± 0.01
 μm) N_1_sea - number of circuli
 Increment_2_sea - scale increment of 2nd marine annual growth
 zone (accuracy ± 0.01 μm) N_2_sea - number of
 circuli Increment_3_sea - scale increment of 3rd marine
 annual growth zone (accuracy ± 0.01 μm) N_3_sea -
 number of circuli Increment_+_sea - plus growth at the
 outer edge of the scale (accuracy ± 0.01 μm) N_+_sea -
 number of circuli Group - hatchery or reared
 fish Sex - 1 -male; 2 - female
 Cohort - year of birth Spawning_1year_before -
 presence of spawning mark one year before capture
 Spawning_2year_before - presence of spawning mark two years
 before capture FishID - individual fish
 number