Sediment and their bacterial communities in an industrialized estuary after Hurricane Harvey

Abstract

Estuaries experience variable physicochemical conditions, especially after hurricanes and due to anthropogenic sources of pollution. Their microbial communities are not as well understood in terms of community structure and diversity, particularly in response to stresses from pollution and severe events. This study presents a 16S rRNA-based description of sediment microbial communities in the Houston Ship Channel-Galveston Bay estuary after Hurricane Harvey in 2017. A total of 11 sites were sampled, and microbial genomic DNA was isolated from sediment. The presence and abundance of specific bacterial and archaeal taxa in the sediment indicated pollutant inputs from identified legacy sources. The abundance of certain microbial groups was explained by the mobilization of contaminated sediment and sediment transport due to Harvey. Several microorganisms involved in the biodegradation of xenobiotics were observed. The spatial occurrence of Dehalococcoidia, a degrader of persistent polychlorinated compounds, was explained in relation to sediment properties and contaminant concentrations.

Keywords: 16S rRNA; Biodegradation; Contamination; Illumina sequencing; Taxa.