Potential impacts of ocean acidification on the Puget Sound food web (NCEI Accession 0134852)

The ecosystem impacts of ocean acidification (OA) were explored by imposing scenarios designed to mimic OA on a food web model of Puget Sound, a large estuary in the northwestern USA. Productivity of functional groups that contain mostly calcifiers was decreased while still allowing other species groups to respond to the scenarios in a dynamic way through indirect effects. Results focus on changes in ecosystem services and structure. Sometimes, the direct and indirect effects of OA countered each other due to interactions between predators and prey within the food web, leading to little change in the food web. In other cases, direct and indirect effects caused greater change in the food web than anticipated from direct effects alone. Results were strongly affected by the group on which OA was directly imposed, with changes in copepod productivity being the most influential. While there is much uncertainty in our predictions, focusing on the complex interactions among species and between species and their environment will yield better understanding of how ecosystems may respond to OA.

本研究通过构建模拟海洋酸化（Ocean Acidification, OA）的多情景方案，作用于美国西北部大型河口——普吉特湾的食物网模型，以此探究海洋酸化对生态系统的影响。以钙化生物为主的功能群的生产力有所下降，同时其他物种类群可通过间接效应动态响应该酸化情景。研究结果聚焦于生态系统服务与生态系统结构的变化。有时，由于食物网内捕食者与猎物间的相互作用，海洋酸化的直接效应与间接效应会相互抵消，最终使得食物网几乎未发生明显变化。在其他情形下，直接效应与间接效应共同作用引发的食物网变化，远超仅通过直接效应所预期的幅度。研究结果受酸化直接作用的功能群影响显著，其中桡足类生产力的变化对结果的影响最为突出。尽管本研究的预测尚存诸多不确定性，但聚焦物种间以及物种与环境间的复杂相互作用，将有助于更深入地理解生态系统对海洋酸化的响应机制。