Diatoms control nutrient cycles in a temperate, wave-dominated estuary (southeast Australia)

Abstract

Diatoms are important primary producers within pelagic, benthic, and epiphytic communities, and their siliceous frustules sink rapidly to the sediment. We measured benthic nutrient and gas fluxes and water column and sediment properties in an estuary of southeastern Australia to identify control mechanisms coupling benthic and pelagic processes, in particular, how nutrients become fractionated by processes affecting benthic nutrient fluxes. During late spring, the water column of St. Georges Basin was oligotrophic, primary production was likely phosphorus (P) limited, and the phytoplankton community was dominated by cyanophytes. Molar ratios of dissolved inorganic carbon (TCO2) to silica (Si..