Woodson C Brock, Litvin Steven Y
Coastal Oceanography and Biophysical Integrated Analysis Laboratory, College of Engineering, University of Georgia, Athens, GA 30601; and
Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950.
Proc Natl Acad Sci U S A. 2015 Feb 10;112(6):1710-5. doi: 10.1073/pnas.1417143112. Epub 2015 Jan 26.
Long-term changes in nutrient supply and primary production reportedly foreshadow substantial declines in global marine fishery production. These declines combined with current overfishing, habitat degradation, and pollution paint a grim picture for the future of marine fisheries and ecosystems. However, current models forecasting such declines do not account for the effects of ocean fronts as biogeochemical hotspots. Here we apply a fundamental technique from fluid dynamics to an ecosystem model to show how fronts increase total ecosystem biomass, explain fishery production, cause regime shifts, and contribute significantly to global biogeochemical budgets by channeling nutrients through alternate trophic pathways. We then illustrate how ocean fronts affect fishery abundance and yield, using long-term records of anchovy-sardine regimes and salmon abundances in the California Current. These results elucidate the fundamental importance of biophysical coupling as a driver of bottom-up vs. top-down regulation and high productivity in marine ecosystems.
据报道，营养物质供应和初级生产的长期变化预示着全球海洋渔业产量将大幅下降。这些下降加上当前的过度捕捞、栖息地退化和污染，给海洋渔业和生态系统的未来描绘了一幅严峻的图景。然而，目前预测此类下降的模型并未考虑海洋锋面作为生物地球化学热点的影响。在此，我们将流体动力学的一项基本技术应用于生态系统模型，以展示锋面如何增加生态系统总生物量、解释渔业产量、导致生态系统状态转变，并通过替代营养途径输送营养物质，从而对全球生物地球化学收支做出重大贡献。然后，我们利用加利福尼亚洋流中凤尾鱼-沙丁鱼种群和鲑鱼数量的长期记录，说明海洋锋面如何影响渔业丰度和产量。这些结果阐明了生物物理耦合作为海洋生态系统中自下而上与自上而下调节以及高生产力驱动因素的根本重要性。
