Seagrass nutrient uptake influenced by below-ground sulphide: a split-chamber hydroponic experiment.

Rhizome sections of Halophila ovalis were collected from the Swan River Estuary at Pelican Point (31°59 S, 115°49 E) in January 2006 and were planted into a hydroponic, split-chamber experiment with constant water flow, designed to only expose below-ground seagrass biomass to sulphide. Sulphide concentrations were maintained at 0, 0.25 and 1 and 4 mM S2- and uptake of seagrass measured by removal of phosphate and ammonium from below-ground water. It was hypothesised that exposure of Halophila ovalis to below-ground sulphide would inhibit the capacity for ammonium and phosphate uptake and photosynthetic efficiency would be reduced.