Dataset: Consequences of trait-selective fisheries on population reproductive potential: an experimental approach

Fish vulnerability to fishing depends on a range of life-history, behavioural and physiological traits which are usually correlated with reproductive success. The present study aims to test if differences in individual catchability (vulnerability-to-angling) may be indirectly affecting the reproductive potential at the population level. Vulnerability-to-angling were experimentally assessed on adult Serranus scriba, a species targeted by recreational fisheries, classifying fish into three categories: high, medium and low vulnerability. Then, fish were grouped in tanks of 13 individuals (each category per duplicate), and monitored throughout a full spawning season to assess differences in seasonal patterns of spawning, total egg production, egg viability and egg quality. Seasonal patterns, egg production and viability did not differed between vulnerability groups. However, low vulnerability fish produced eggs with bigger egg yolk compared to high vulnerability fish but only towards the end of the spawning season. This difference may suggest that in unexploited populations, low vulnerability fish may contribute little to year class strength in typical years but might act as a buffer if a disturbance affects reproductive success early in the season. Moreover, these results support the hypothesis that harvested populations may compensate for the harvested biomass by investing more energy per fish in reproduction.

鱼类捕捞易感性（fish vulnerability to fishing）取决于一系列生活史、行为学与生理学特征，而这些特征通常与繁殖成功率紧密相关。本研究旨在检验个体可捕捞性（individual catchability，即垂钓易损性vulnerability-to-angling）的差异是否会间接影响种群层面的繁殖潜力。研究以休闲渔业的目标物种纹斑鲈（Serranus scriba）成鱼为实验对象，通过实验评估其垂钓易损性，并将个体划分为高、中、低三个易损性等级。随后将鱼类按每个养殖缸（tank）13尾的规格分组，每个易损性等级设置两个重复组，并在完整的产卵季内开展持续监测，以评估各组在产卵季节模式、总产卵量、卵活力及卵品质上的差异。结果显示，不同易损性等级的个体在产卵季节模式、总产卵量及卵活力方面均无显著差异，但仅在产卵季末期，低易损性个体所产鱼卵的卵黄体积显著高于高易损性个体。这一差异表明，在未开发的种群中，低易损性个体在常规年份对年群补充量（year class strength）的贡献有限，但当繁殖季早期遭遇干扰并影响繁殖成功率时，这类个体可充当种群的缓冲储备。此外，本研究结果支持以下假说：被开发的种群可通过提升单条个体的繁殖能量投入，来弥补捕捞所损失的生物量。