Espinasse Boris, Hunt Brian P V, Finney Bruce P, Fryer Jeffrey K, Bugaev Alexander V, Pakhomov Evgeny A
Department of Earth, Ocean and Atmospheric Sciences University of British Columbia Vancouver British Columbia Canada.
Institute for the Oceans and Fisheries University of British Columbia AERL Vancouver BC Canada.
Ecol Evol. 2020 Nov 13;10(23):13555-13570. doi: 10.1002/ece3.7022. eCollection 2020 Dec.
The stock-specific distribution of maturing salmon in the North Pacific has been a persistent information gap that has prevented us from determining the ocean conditions experienced by individual stocks. This continues to impede understanding of the role of ocean conditions in stock-specific population dynamics. We assessed scale archives for 17 sockeye salmon () stocks covering the entire North Pacific, from the Columbia River (Washington State and British Columbia) to Kamchatka Peninsula (Russia), to infer salmon locations during their last growing season before returning to their spawning grounds. The approach used, first pioneered in salmon stocks in the Atlantic, relies on the relationship between temporal changes in δC in salmon scales and sea surface temperature to estimate salmon distribution based on correlation strength. An advantage of this approach is that it does not require fish sampling at sea, but relies on existing fishery agency collections of salmon scales. Significant correlations were found for 7 of the stocks allowing us to propose plausible feeding grounds. Complementary information from δN, historical tagging studies, and connectivity analysis were used to further refine distribution estimates. This study is a first step toward estimating stock-specific distributions of salmon in the North Pacific and provides a basis for the application of the approach to other salmon scale archives. This information has the potential to improve our ability to relate stock dynamics to ocean conditions, ultimately enabling improved stock management. For example, our estimated distributions of Bristol Bay and NE Pacific stocks demonstrated that they occupy different areas with a number of the former being distributed in the high productivity shelf waters of the Aleutian Islands and Bering Sea. This may explain why these stocks seem to have responded differently to changes in ocean conditions, and the long-term trend of increased productivity of Bristol Bay sockeye.
北太平洋成熟鲑鱼的种群特定分布一直是一个长期存在的信息空白，这使我们无法确定各个种群所经历的海洋条件。这继续阻碍着我们理解海洋条件在种群特定的种群动态中的作用。我们评估了覆盖整个北太平洋的17种红大麻哈鱼种群的鳞片档案，范围从哥伦比亚河（华盛顿州和不列颠哥伦比亚省）到堪察加半岛（俄罗斯），以推断鲑鱼在返回产卵地之前最后一个生长季节的位置。所采用的方法最初是在大西洋的鲑鱼种群中开创的，它依赖于鲑鱼鳞片中δC的时间变化与海面温度之间的关系，根据相关强度来估计鲑鱼的分布。这种方法的一个优点是不需要在海上对鱼类进行采样，而是依赖于渔业机构现有的鲑鱼鳞片收集。在7个种群中发现了显著的相关性，这使我们能够提出合理的觅食地。来自δN、历史标记研究和连通性分析的补充信息被用于进一步完善分布估计。这项研究是估计北太平洋鲑鱼种群特定分布的第一步，并为将该方法应用于其他鲑鱼鳞片档案提供了基础。这些信息有可能提高我们将种群动态与海洋条件联系起来的能力，最终实现更好的种群管理。例如，我们对布里斯托尔湾和东北太平洋种群的估计分布表明，它们占据不同的区域，前者中有许多分布在阿留申群岛和白令海高生产力的陆架水域。这或许可以解释为什么这些种群对海洋条件变化的反应似乎不同，以及布里斯托尔湾红大麻哈鱼生产力长期上升的趋势。
