Knowledge of the ecological mechanisms that influence recovery after oil spills is needed to better manage, mitigate, and restore impacted ecosystems, but the species interactions responsible for these mechanisms are poorly known. Here, we report on a species interaction in the aftermath of the Deepwater Horizon (DwH) oil spill that may facilitate biotic recovery. Although macroinfauna were extirpated in heavily oiled salt marshes after the DwH, amphipods recovered by 4.5 years, and maintained elevated densities, up to 20 × higher, compared to reference sites for 2 years thereafter. Many invertebrates were recovering during this period, and we compared the densities of 10 taxa with the density of amphipods to ask if recovery may have been affected by the abundance of amphipods. Correlation analysis revealed that copepod species richness and the densities of the polychaete Manayunkia aestuarina, ostracods, the kinorhynch Echinoderes coulii, and juvenile gastropods were unrelated to amphipod density. However, the densities of nematodes, copepods (adults and larvae), the tanaid Hargeria rapax, juvenile bivalves, and juvenile polychaetes were positively correlated with amphipod abundance. More than 90% of the amphipods were Apocorophium louisianum. Studies with closely related species indicate that this species is a burrowing and bioturbating ecosystem engineer that grazes benthic microalgae. We hypothesize that amphipod grazing increased the supply and/or availability of microalgae to surface- and suspension-feeding invertebrates either by stimulating microalgal primary production or by suspending microalgal particles, or both. The high abundance of amphipods may therefore have enhanced the resilience of, and ecological benefits provided by, many benthic invertebrates in heavily oiled marshes undergoing ecosystem recovery.

需要了解影响石油泄漏后恢复的生态机制，以更好地管理、减轻和恢复受影响的生态系统，但对这些机制的物种相互作用知之甚少。在这里，我们报告了深水地平线之后的物种相互作用(DwH) 可能促进生物恢复的石油泄漏。尽管在 DwH 之后大型动物在重油盐沼中灭绝，但片脚类动物恢复了 4.5 年，并在此后的 2 年中保持了比参考地点高 20 倍的高密度。在此期间，许多无脊椎动物正在恢复，我们将 10 个分类群的密度与片脚类动物的密度进行了比较，以了解恢复过程是否受到片脚类动物数量的影响。相关性分析表明，桡足类物种丰富度和多毛纲Manayunkia aestuarina、介形动物、动吻棘皮动物和幼年腹足动物的密度与片脚类动物密度无关。然而，线虫、桡足类（成虫和幼虫）的密度，tanaidHargeria rapax、幼年双壳类和幼年多毛类与片脚类动物丰度呈正相关。超过 90% 的片脚类动物是Apocorophium louisianum。对密切相关物种的研究表明，该物种是一种穴居和生物扰动的生态系统工程师，以放牧底栖微藻为生。我们假设片脚类动物的放牧通过刺激微藻初级生产或悬浮微藻颗粒，或两者兼而有之，增加了微藻对表面和悬浮喂养的无脊椎动物的供应和/或可用性。因此，片脚类动物的高丰度可能增强了正在经历生态系统恢复的重油沼泽中许多底栖无脊椎动物的复原力和生态效益。