Evidence of Rapid Functional Benthic Recovery Following the Deepwater Horizon Oil Spill

The 2010 Deepwater Horizon incident was a massive deep-sea
oil
spill and resulted in deposition of hydrocarbons at the seafloor surface.
Soft sediment benthic macrofauna provide critical global ecosystem
services, and little is known about their recovery trajectories from
similar disturbances in the deep sea. Recent publications report an
initial opportunistic benthic infaunal response and predict 50–100
years for recovery of species-level diversity, abundance, and composition.
Sediment profile and plan view imaging data collected at depths from
1040 to 1689 m in 2011 and 2014 not only confirm this opportunistic
response but also indicate further stages of functional benthic recovery.
The recovery trajectory mimicked benthic succession following organic
enrichment that is widely recorded in coastal systems but not the
deep sea. Bioturbating taxa were present deep in the sediment column
in both years. In 2014, a decline in the relative abundance of opportunistic
taxa and a positive rebound in the apparent redox potential discontinuity
depth, an integrated measure of biogeochemical functioning, were recorded.
These results suggest that bioturbation-mediated microbial degradation
is a plausible mechanism by which rapid functional benthic recovery
occurred. With oil and gas extraction prevalent in the deep sea, improving
the understanding of benthic recovery in these environments is critical.