Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA.
Department of Biological Sciences, Virginia Institute of Marine Science, William & Mary, Gloucester Point, VA, 23062, USA.
Mar Environ Res. 2020 Mar;155:104881. doi: 10.1016/j.marenvres.2020.104881. Epub 2020 Jan 23.
Given the severity of injuries to biota in coastal wetlands from the Deepwater Horizon oil spill (DWH) and the resulting availability of funding for restoration, information on impacted salt marshes and biotic development of restored marshes may both help inform marsh restoration planning in the near term and for future spills. Accordingly, we performed a meta-analysis to model a restoration trajectory of total macroinfauna density in constructed marshes (studied for ~30 y), and with a previously published restoration trajectory for amphipods, we compared these to recovery curves for total macroinfauna and amphipods from DWH impacted marshes (over 8.5 y). Total macroinfauna and amphipod densities in constructed marshes did not consistently reach equivalency with reference sites before 20 y, yet in heavily oiled marshes recovery occurred by 4.5 y post spill (although it is unlikely that macroinfaunal community composition fully recovered). These differences were probably due to initial conditions (e.g., higher initial levels of belowground organic matter in oiled marshes) that were more conducive to recovery as compared to constructed marshes. Furthermore, we found that amphipod trajectories were distinctly different in constructed and oiled marshes as densities at oiled sites exceeded that of reference sites by as much as 20x during much of the recovery period. Amphipods may have responded to the rapid increase and high biomass of benthic microalgae following the spill. These results indicate that biotic responses after an oil spill may be quantitatively different than those following restoration, even for heavily oiled marshes that were initially denuded of vegetation. Our dual trajectories for oil spill recovery and restoration development for macroinfauna should help guide restoration planning and assessment following the DWH as well as for restoration scaling for future spills.
鉴于深水地平线（Deepwater Horizon，DWH）溢油事件对沿海湿地生物群的严重伤害，以及由此产生的恢复资金可用性，受影响的盐沼和恢复后的沼泽生物的发展信息都可能有助于短期和未来溢油事件的沼泽恢复规划。因此，我们进行了荟萃分析，以模拟人工湿地中总大型底栖无脊椎动物密度的恢复轨迹（研究了约 30 年），并与以前发表的滨螺恢复轨迹进行了比较，将这些轨迹与 DWH 受影响的沼泽中的总大型底栖无脊椎动物和滨螺的恢复曲线进行了比较（超过 8.5 年）。在 20 年之前，人工湿地中的总大型底栖无脊椎动物和滨螺密度并未始终达到参考点的等效水平，但在重度油污染的沼泽中，溢油后 4.5 年就出现了恢复（尽管大型底栖无脊椎动物群落组成不太可能完全恢复）。这些差异可能是由于初始条件（例如，受污染的沼泽中地下有机物质的初始水平较高）与人工湿地相比更有利于恢复。此外，我们发现，在人工湿地和受污染的沼泽中，滨螺的轨迹明显不同，因为在大部分恢复期间，受污染地点的密度比参考点高 20 倍。滨螺可能对溢油后底栖微藻的快速增加和高生物量做出了响应。这些结果表明，即使对于最初植被被剥蚀的重度油污染沼泽，溢油后的生物响应在数量上可能与恢复后的生物响应不同。我们的大型底栖无脊椎动物溢油恢复和恢复发展的双轨迹应该有助于指导 DWH 后的恢复规划和评估，以及未来溢油事件的恢复规模。
