Methanotroph community structure and processes in an inland river affected by natural gas macro-seeps

Abstract

Methane availability in freshwaters is usually associated with spatialoral variation in methanogenesis. Unusually, however, natural gas macro-seeps occur along the Condamine River in eastern Australia which elevate ambient water-column methane concentrations more than 3,000 times. We quantified the spatialoral variation in methane oxidation rates and the total microbial and methanotroph community composition (through the amplification and sequencing of 16S rRNA and particulate methane monooxygenase (pmoA) genes), and the factors mediating this variation, in reaches with and without macro-seeps. Sediment methane oxidation rates were, on average, 29 times greater, and the abundance of methanot..