ABSTRACT
The Deepwater Horizon oil spill resulted in persistent heavy oiling in salt marshes, particularly in northern Barataria Bay, Louisiana. Oiling conditions and several ecological variables were compared among reference plots and three types of heavily oiled plots located along a continuous shoreline area in northern Barataria Bay: oiled control plots, mechanical treatment plots, and mechanical treatment plots coupled with vegetation planting (Spartina alterniflora). Data were collected more than three years following initial oiling and two years following cleanup treatments and planting. Salt marsh oiling and associated impacts were apparent across all oiling/treatment classes relative to reference conditions. Mechanical treatment with planting showed the most improvement in oiling conditions and was also effective in re-establishing vegetation cover and plant species composition similar to reference conditions, in contrast to the oiled controls and mechanical treatment plots without planting. Marsh periwinkle (Littoraria irrorata) recovery was limited across all oiling/treatment classes relative to reference. Impacts to fiddler crabs (Uca spp.) were also documented in the heavily oiled plots. Positive influences of mechanical treatment and planting on macroinvertebrate recovery were observed; however, invertebrate recovery may lag the return of Spartina alterniflora by several years. Vegetation planting should be considered as a spill response and emergency restoration option for heavily oiled salt marshes where vegetation impacts are substantial, natural recovery may be lacking or delayed, intensive cleanup treatments are used, or where marsh shorelines are at risk of erosion.
Meta‐analysis of salt marsh vegetation impacts and recovery: a synthesis following the
Deepwater Horizon
oil spill
