Abstract
AbstractThe resilience of sea trout populations is increasingly concerning, with evidence of major demographic changes in some populations. Based on trapping data and related scale collec-tion, we analysed long-term changes in body length of a sea trout population in the Bresle River, France. From 1984-2022, the length of first-time returning individuals decreased by 1.18 mm.year-1 (SD = 0.03), which resulted in the loss ofc.8% of mean body length. This decrease results from a decrease in the age at first return, with a gradual loss of the oldest individuals and an increase in the proportion of the youngest. Timing of the return migration advanced drastically, although shorter sea sojourn had little influence on body length. We found little evidence of a decrease in length-at-age, to the exception of the oldest age class, suggesting that growth conditions at sea might not have deteriorated greatly during the study period.
Publisher
Cold Spring Harbor Laboratory
Reference104 articles.
1. A new look at the statistical model identification
2. Compensatory growth offsets poor condition in native trout populations
3. The Interplay Between Extrinsic and Intrinsic Factors in Determining Migration Decisions in Brown Trout (Salmo trutta): An Experimental Study
4. Baglinière, J.-L. , Hamelet, V. , Guéraud, F. , Aymes, J.-C. , Goulon, C. , Richard, A. , Josset, Q. , Marchand, F. , 2020. Guide to the interpretation of the scales and the estimation of the age of brown trout (Salmo trutta) from the French populations., Guides and. ed.
5. Evidence for long-term change in length, mass and migration phenology of anadromous spawners in French Atlantic salmonSalmo salar