College of Marine Science. University of South Florida. 140 7th St. Petersburg, FL. 33701, USA.
Harte Research Institute. Texas A&M University-Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX, 78412-5869, USA.
Environ Pollut. 2023 Jan 1;316(Pt 1):120450. doi: 10.1016/j.envpol.2022.120450. Epub 2022 Oct 20.
Field studies showed that benthic macrofauna and meiofauna abundances increased with sediment oil concentration in areas affected by the Deepwater Horizon (DWH) oil spill. Benthic invertebrate biomass shows a dome-shaped relationship with respect to petrogenic hydrocarbon concentrations suggesting a positive effect on biomass at low-to-medium oil concentrations and a negative effect at high concentrations. If this is due to enrichment of the benthic food web, then this adds to an emerging picture of a food web response over a large spatial area with both abundance increases and decreases as a result of DWH. We would be obliged to consider long term multispecies effects beyond the initial pulse disturbance in modeling impacts and recovery of economically valuable species. An Atlantis ecosystem model of the Gulf of Mexico is used to simulate three mechanisms that could explain observed changes in the invertebrate community. Scenario 1 is that stimulation of surface primary productivity occurred as a result of nutrient loading caused by diversion of Mississippi River water into Barataria Bay (a mitigation action taken during the DWH oil spill). Scenario 2 is that enrichment of the benthos occurred due to detrital loading from marine oil snow sedimentation and flocculent accumulation (MOSSFA). Scenario 3 is that predator declines and/or avoidance of oiled areas caused a release of predation mortality on benthic invertebrates. Scenario 2 (MOSSFA) stimulated the detritus-driven food web and was best able to cause a net increase in invertebrate biomass despite a realistic amount of oil toxicity. Scenario 3 (predator release) plausibly could have contributed to changes in benthic invertebrates. Scenario 1 (nutrient loading) had little impact on the benthos suggesting the benthic food web is decoupled from local pelagic production sources.
实地研究表明，在受深水地平线（DWH）溢油事件影响的区域，底栖大型动物和小型动物的丰度随着沉积物中石油浓度的增加而增加。底栖无脊椎动物生物量与源自石油的碳氢化合物浓度呈圆顶形关系，表明在低至中等石油浓度下对生物量有积极影响，而在高浓度下则有负面影响。如果这是由于底栖食物网的富集所致，那么这就增加了一个正在出现的图景，即在一个大的空间区域内，由于 DWH，底栖食物网的反应既有丰度的增加，也有减少。我们将不得不考虑在建模影响和经济价值物种的恢复方面，除了初始脉冲干扰之外，长期的多物种效应。利用墨西哥湾的 Atlantis 生态系统模型来模拟三种机制，这些机制可以解释无脊椎动物群落中观察到的变化。情景 1 是由于密西西比河河水改道流入巴塔利亚湾（DWH 溢油事件期间采取的一种缓解措施）导致营养物质负荷增加，从而刺激了地表初级生产力。情景 2 是由于海洋石油雪沉积物和絮状物积累造成的底栖富营养化（MOSSFA）。情景 3 是由于捕食者减少和/或避免受油污染的区域，导致底栖无脊椎动物的捕食死亡率释放。情景 2（MOSSFA）刺激了碎屑驱动的食物网，尽管存在相当数量的石油毒性，但仍能最有效地导致无脊椎动物生物量的净增加。情景 3（捕食者释放）可能对底栖无脊椎动物的变化做出了贡献。情景 1（营养负荷）对底栖生物几乎没有影响，这表明底栖食物网与当地的浮游生产源脱钩。
