Fig 1.
Location of core sampling sites in the northeastern Gulf of Mexico with reference to the Deepwater Horizon.
Table 1.
Short-lived radioisotope (210Pb, 234Th) activities, constant rate of supply age model, total organic carbon (TOC) percentages and TOC accumulation rates with depth for each core [29].
Fig 2.
Core photographs and densities (indiv./cm3) of the benthic foraminifera genera throughout the surface sections of each core site including gray areas representing the decline in benthic foraminifera density in each record and the corresponding date.
Table 2.
Number of dominant genera with depth for each core and the corresponding BFAR.
Fig 3.
Benthic foraminiferal accumulation rate (BFAR) records for each sampling site with the period from 2007–2011 expanded for examination of the period during and after the DWH event.
The gray areas represent the decline in BFAR and the gray lines represent the down-core mean BFAR.
Fig 4.
Non-metric multidimensional scaling plots for each core, where black dots represent the foraminiferal density at each sample interval (depths labeled in blue) and green vectors represent each environmental variable (HMW PAH, LMW PAH, Re, Mn)[28,29].
The Euclidian distance between each sample depth represents the Bray Curtis similarity and the orientation and length of the green vectors represent the correspondence and intensity of each environmental parameter to the variability between foraminiferal density.
Fig 5.
Total benthic foraminiferal density (indiv./cm3), low molecular weight polycyclic aromatic hydrocarbon concentrations (LMW PAH, ng/g dw)[29], and redox sensitive metal (Re, Mn)[28] records stacked using short-lived radioisotope geochronology.
Pre-DWH and post-DWH periods are denoted with their respective mass accumulation rates in the gray-shaded areas and the down-core means for benthic foraminiferal density and LMW PAH are represented by black lines.
Table 3.
Mean impacted and control benthic foraminiferal densities (indiv./cm−3) from this study are presented with three previous records of total surface benthic foraminiferal densities (indiv./cm−3) collected at natural seep sites and along the continental slope of the northern Gulf of Mexico.