Changes in length-at-first return of a sea trout (*Salmo trutta*) population in northern Franceuse asterix (*) to get italics

Quentin Josset, Laurent Beaulaton, Atso Romakkaniemi, Marie NevouxPlease use the format "First name initials family name" as in "Marie S. Curie, Niels H. D. Bohr, Albert Einstein, John R. R. Tolkien, Donna T. Strickland"

2024

<p style="text-align: justify;">The resilience of sea trout populations is increasingly concerning, with evidence of major demographic changes in some populations. Based on trapping data and related scale collection, 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 1.73 mm.year-1 (SD = 0.08), which resulted in the loss of c. 12.3% 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.</p>

https://doi.org/10.57745/FPHLBTYou should fill this box only if you chose 'All or part of the results presented in this preprint are based on data'. URL must start with http:// or https://

https://doi.org/10.5281/zenodo.10199683You should fill this box only if you chose 'Scripts were used to obtain or analyze the results'. URL must start with http:// or https://

age structure; body length; life history; marine growth; migration; sea trout

NonePlease indicate the methods that may require specialised expertise during the peer review process (use a comma to separate various required expertises).

Biodiversity, Evolutionary ecology, Freshwater ecology, Life history, Marine ecology

Eva Thorstad, eva.thorstad@nina.no, Jan Ohlberger, janohl@uw.edu, Elvira de Eyto, elvira.deeyto@marine.ie, Nigel Milner, n.milner@apemltd.co.uk, Russel Poole, russell.poole@marine.ie, Stephen Gregory, stephen.gregory@cefas.gov.uk, Jan Grimsrud Davidsen, jan.davidsen@ntnu.no, Asta Audzijonyte [asta.audzijonyte@utas.edu.au] suggested: Apologies, I am completely overloaded with work and review invitations. I could recommend Dr Barrett Wolfe (University of Tasmania) as an alternative reviewer. barrett.wolfe@utas.edu.au , Jan Davidsen [jan.davidsen@ntnu.no] suggested: Mikkel friis mikkel.e.l.friis@ntnu.no, Barrett Wolfe [barrett.wolfe@utas.edu.au] suggested: t.tinhan@gmail.com, Stephen Gregory [stephen.gregory@cefas.gov.uk] suggested: Jessica Marsh jessica.marsh@cefas.gov.uk. No need for them to be recommenders of PCIEcology. Please do not suggest reviewers for whom there might be a conflict of interest. Reviewers are not allowed to review preprints written by close colleagues (with whom they have published in the last four years, with whom they have received joint funding in the last four years, or with whom they are currently writing a manuscript, or submitting a grant proposal), or by family members, friends, or anyone for whom bias might affect the nature of the review - see the code of conduct

2023-11-23 14:36:39

Aleksandra Walczyńska