了解驱动种群或物种之间空间同步的因素对于种群的管理和恢复非常重要。大西洋鲑鱼(Salmosalar)种群的广泛下降可能是海洋环境广泛变化的结果。鲑鱼在海洋中迅速生长;因此,不断变化的海洋条件可能会影响用于评估是否满足种群参考点的体型和繁殖力估计。使用一个跨越五十年的数据集,172,268人,和加拿大东部的19条河流,我们调查了返回的野生成年大西洋鲑鱼的体型变化中空间同步性的发生。然后,体型与海洋环境条件相关(即,气候指数,热栖息地可用性,食物供应,密度依赖性,和渔业开采率),可能在其生命周期的海洋摄食阶段对所有种群起作用。在1980年代和1990年代,鲑鱼的体型在一个(1SW)或两个冬天(2SW)后返回河流;但是,仅在一些中纬度和北部河流(在这几十年中有10年以上数据的10/13河流)和南部河流(0/2)中观察到1SW和/或2SW的显着变化,表明加拿大东部的空间同步较弱。对于9条河流的1SW鲑鱼,当渔业开采率较低时,体型较长。对于2SW鲑鱼,当合适的热栖息地更丰富(对3/8河流显著)并且大西洋年代际振荡更高(即,较暖的海面温度;对4/8河流显著)。总的来说,协变量对河流体型的弱空间同步性和可变效应表明,大西洋鲑鱼体型的变化可能不仅仅是由海洋环境中的共同条件驱动的。无论如何,通过大小与繁殖力之间的关系,身体大小的变化可能对人口管理和恢复产生影响。
Understanding the factors that drive spatial synchrony among populations or species is important for management and recovery of populations. The range-wide declines in Atlantic salmon (Salmo salar) populations may be the result of broad-scale changes in the marine environment. Salmon undergo rapid growth in the ocean; therefore changing marine conditions may affect body size and fecundity estimates used to evaluate whether stock reference points are met. Using a dataset that spanned five decades, 172,268 individuals, and 19 rivers throughout Eastern Canada, we investigated the occurrence of spatial synchrony in changes in the body size of returning wild adult Atlantic salmon. Body size was then related to conditions in the marine environment (i.e., climate indices, thermal habitat availability, food availability, density-dependence, and fisheries exploitation rates) that may act on all populations during the ocean feeding phase of their life cycle. Body size increased during the 1980s and 1990s for salmon that returned to rivers after one (1SW) or two winters at sea (2SW); however, significant changes were only observed for 1SW and/or 2SW in some mid-latitude and northern rivers (10/13 rivers with 10 of more years of data during these decades) and not in southern rivers (0/2), suggesting weak spatial synchrony across Eastern Canada. For 1SW salmon in nine rivers, body size was longer when fisheries exploitation rates were lower. For 2SW salmon, body size was longer when suitable thermal habitat was more abundant (significant for 3/8 rivers) and the Atlantic Multidecadal Oscillation was higher (i.e., warmer sea surface temperatures; significant for 4/8 rivers). Overall, the weak spatial synchrony and variable effects of covariates on body size across rivers suggest that changes in Atlantic salmon body size may not be solely driven by shared conditions in the marine environment. Regardless, body size changes may have consequences for population management and recovery through the relationship between size and fecundity.