Perturbation of seafloor bacterial community structure by drilling waste discharge

• Published in: Marine Pollution Bulletin
• Main Authors: Nguyen, Tan Thi, Cochrane, Sabine K.J., Landfald, Bjarne
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2017
• Subjects: Drill cutting; Seafloor; Bioindicator; Microbiota; Barents Sea; VDP::Teknologi: 500::Berg‑ og petroleumsfag: 510; VDP::Teknologi: 500::Marin teknologi: 580::Offshoreteknologi: 581; VDP::Technology: 500::Marine technology: 580::Offshore technology: 581; VDP::Technology: 500::Rock and petroleum disciplines: 510
• Online Access: https://hdl.handle.net/10037/12404; https://doi.org/10.1016/j.marpolbul.2017.10.039

Published version available in Marine Pollution Bulletin, 2017. Offshore drilling operations result in the generation of drill cuttings and localized smothering of the benthic habitats. This study explores bacterial community changes in the in the upper layers of the seafloor resulting from an exploratory drilling operation at 1400 m water depth on the Barents Sea continental slope. Significant restructurings of the sediment microbiota were restricted to the sampling sites notably affected by the drilling waste discharge, i.e. at 30 m and 50 m distances from the drilling location, and to the upper 2 cm of the seafloor. Three bacterial groups, the orders Clostridiales and Desulfuromonadales and the class Mollicutes, were almost exclusively confined to the upper two centimeters at 30 m distance, thereby corroborating an observed increase in anaerobicity inflicted by the drilling waste deposition. The potential of these phylogenetic groups as microbial bioindicators of the spatial extent and persistence of drilling waste discharge should be further explored.