RAPID: Community-level Wetland Stressors, Northern Gulf of Mexico

这个项目解决了由墨西哥湾深水地平线漏油事件引起的路易斯安那州盐沼生物群落变化的科学问题。一组经验丰富的调查人员将在2010年9月和2011年5月对35个以上的盐沼进行采样，这是对2010年5月从这些地点收集的样本的补充。因此，采样将涵盖沼泽上油之前、生长季节高峰期和一年后的一段时间。将收集关于优势水生植物(线草、互花米草)的生物量、土壤代谢、硫积累的变化、稳定的同位素特征、固氮率以及寄生和共生无脊椎动物群落的数据。收集的数据将被用来检验关于长期和长期应激源(石油、毒素、分散剂或营养物质)对盐沼生态系统的影响的各种假设，包括对盐沼社区的间接长期后果的预测。这一异常大的漏油事件提供了一个不同寻常的机会来了解对生态系统的短期和长期应激源，但前提是有足够大和不同的基线测量。环境压力因素，如碳氢化合物泄漏引起的环境压力，由于对生物体的物理和毒性影响，可能对沿海生态系统产生明显和直接的影响。应激源也有间接影响，因为当它们开始降解时，这些化合物通过主要消费者进入食物网，如悬浮摄食的牡蛎、沉积物摄食的双壳贝类和食草性蜗牛。反过来，这些消费者是包括人类在内的营养水平较高的生物的食物来源。因此，随着较低营养水平的成员经历生长、死亡和繁殖成功的变化，以及物种周转和新陈代谢途径的改变，主要环境应激源的影响可以级联到整个群落。该项目的目标是提供沼泽生态系统变化的基准研究，并及时预测替代状态，以便采取补偿管理行动。

This project addresses scientific questions about changes in the biological community of Louisiana salt marshes caused by the Deepwater Horizon oil spill in the Gulf of Mexico. A team of experienced investigators will sample 35+ salt marshes in September 2010 and May 2011, adding to the samples already collected from these sites in May 2010. Thus, the sampling will cover the periods before the marshes are oiled, at the peak of the growing season, and one year later. Data will be collected on the biomass of the dominant aquatic plant (cordgrass, Spartina alterniflora), soil metabolism, changes in sulfur accumulation, stable isotope signatures, nitrogen fixation rate, and the parasitic and symbiotic invertebrate community. The data collected will be used to test various hypotheses about the effects of chronic and long-term stressors (oil, toxins, dispersants, or nutrients) on salt marsh ecosystems, including predictions about indirect long-term consequences to the salt-marsh community.This exceptionally large oil spill event provides an unusual opportunity to learn about the short- and long-term stressors on ecosystems, but only if there are sufficiently large and varied baseline measurements. Environmental stressors such as those arising from hydrocarbon spills, can have visible and immediate direct impacts on coastal ecosystems due to physical and toxic effects on organisms. Stressors also have indirect effects because, as they begin to degrade, the compounds enter food webs via primary consumers such as suspension-feeding oysters, deposit-feeding bivalves, and grazing snails. These consumers, in turn, are food sources for organisms at higher trophic levels, including humans. The effects of a major environmental stressor can, therefore, cascade through the community as members of lower trophic levels undergo changes in growth, mortality, and reproductive success, and as species turnover occurs and metabolic pathways are altered. The project goals are to provide a benchmark study in marsh ecosystem change, and to predict alternative states in time for compensatory management actions.