Data from: Does catch and release affect the mating system and individual reproductive success of wild Atlantic salmon (Salmo salar L.)?

In this study, we documented the breeding system of a wild population of Atlantic salmon (Salmo salar L.) by genetically sampling every returning adult and assessed the determinants of individual fitness. We then quantified the impacts of catch and release (C&R) on mating and reproductive success. Both sexes showed high variance in individual reproductive success, and the estimated standardized variance was higher for males (2.86) than for females (0.73). We found a weak positive relationship between body size and fitness and observed that fitness was positively correlated with the number of mates, especially in males. Mature male parr sired 44% of the analysed offspring. The impact of C&R on the number of offspring was size dependent, as the reproductive success of larger fish was more impaired than smaller ones. Also, there was an interactive negative effect of water temperature and air exposure time on reproductive success of C&R salmon. This study improves our understanding of the complex reproductive biology of the Atlantic salmon and is the first to investigate the impact of C&R on reproductive success. Our study expands the management toolbox of appropriate C&R practices that promote conservation of salmon populations and limit negative impacts on mating and reproductive success.

本研究通过对每一头洄游成年个体开展遗传取样，阐明了大西洋鲑（Salmo salar L.）野生种群的繁殖系统特征，并解析了个体适合度的决定因素。随后本研究量化了捕获后放生（Catch and Release，C&R）对交配成功率与繁殖成功率的影响。研究发现，雌雄两性的个体繁殖成功率均存在较高变异水平，且雄性的标准化估算变异值（2.86）高于雌性（0.73）。本研究观察到体长与个体适合度呈弱正相关关系，同时发现适合度与交配伴侣数量呈正相关，这一现象在雄性个体中尤为显著。性成熟雄性幼鲑所产生的后代占本研究分析后代总量的44%。C&R对后代数量的影响存在体长依赖性：体型更大的个体其繁殖成功率受到的抑制作用较小型个体更为显著。此外，水温与露空时长对接受C&R处理的鲑鱼的繁殖成功率存在交互负向作用。本研究深化了学界对大西洋鲑复杂繁殖生物学的认知，同时亦是首个探究C&R对繁殖成功率影响的相关研究。本研究拓展了合理C&R操作的管理工具箱，此类操作可助力鲑鱼种群保护，并有效降低其对交配与繁殖成功率的负面影响。