Analysis of bacterial diversity and metals in produced water, seawater and sediments from an offshore oil and gas production platform

► Bacterial community and metal analyses of water and sediment performed. ► Produced water bacterial community different from seawater and sediment. ► Sediment bacterial community near platform different from more distant samples. ► Metal concentrations elevated in sediments near the platform. ► Results suggest that observed changes related to discharge of produced water. Produced water is one of the largest waste products routinely discharged into the ocean from offshore oil and gas platforms. This study analyzed bacterial communities and metals in the produced water, surrounding seawater, and sediment around the Thebaud platform. The bacterial community within the produced water was different from the seawater (SAB=13.3), but the discharge had no detectable effect on the bacterial communities in the seawater (SAB>97). In contrast, genomic analysis of sediments revealed that the bacterial community from 250m was different (SAB=70) from other locations further from the discharge, suggesting that the produced water had a detectable effect on the bacterial community in the sediment closest to the discharge. These near-field sediments contained elevated concentrations of manganese and iron that are associated with the produced water effluent. The results suggested that the discharge of produced water has influenced the bacterial community structure of sediments adjacent to the platform.