What Promotes the Recovery of Salt Marsh Infauna After Oil Spills?

Abstract

Many factors influence the rate at which biotic communities recover from environmental disasters, and a thorough understanding of these factors is needed to formulate effective mitigation strategies. The importance of foundation species, soil environmental quality, and benthic microalgae to the long-term recovery of the salt marsh infaunal community following the 2010 Deepwater Horizon oil spill was examined in northern Barataria Bay, LA, from 2011 to 2016. The community of 12 abundant taxa of meiofauna and juvenile macroinfauna began to rebound from oiling in < 2 years, but did not fully recover after 6.5 years. The pace and intensity of recovery of nematodes, copepods, most polychaetes, tanaids, juvenile bivalves, and amphipods were significantly and positively related to the recovery of Spartina alterniflora and benthic microalgae. However, total petroleum hydrocarbon concentrations remained elevated over time, and live belowground plant biomass, bulk density, dead aboveground plant biomass, and live aboveground biomass of Juncus roemerianus were not resilient, indicating that soil quality at oiled sites was insufficient to foster the recovery of the infaunal community as a whole. Recovery of the kinorhynch Echinoderes coulli, the polychaete Manayunkia aestuarina, ostracods, and juvenile gastropods was suppressed in association with these factors. Foundation species enhance salt marsh infaunal recovery by modifying habitat in the short term and improving soil quality over the longer term. Therefore, efforts to enhance the recovery of foundation species (e.g., by plantings) should benefit the recovery of microalgal primary producers and benthic consumers after oiling in salt marshes.