Benthic methane fluxes and oxidation over the Western Indian Shelf: No evidence of pelagic methanotrophic denitrification.

Despite its pelagic supersaturation and wide occurrence of gas-charged pockets in the sediments, methane occurs at unusually low concentrations in the shelf waters off Western Indian coast, even during euxinic events, compared to other anoxic coastal systems of the world. To understand the reason and benthic biogeochemistry of CH, we measured benthic CH flux rates through whole-core incubations, and carried out CH-spiked N-labeled incubations of the suboxic/anoxic shelf waters during 2011-2013. We observed very low rates of benthic CH influx or efflux (-0.