Benthic Nutrient Recycling in Port Phillip Bay, Australia

摘要: Benthic chamber measurements of the reactants and products involved with biogenic matter remineralization (oxygen, ammonium, nitrate, nitrite, phosphate, silicate, TCO2and alkalinity) were used to define solute exchange rates between sediment overlying water column Port Phillip Bay, Australia. Measurements at various sites throughout bay, conducted during summers 1994 1995, indicate that variability in flux values within a site is comparable year-to-year (±50%). Four regions bay distinguished by properties northern region was identified as having 3–30 times greater nutrient regeneration than other regions. recycling accounted for 63 72% annualized N P input, respectively, entire determined summing benthic, dissolved riverine, atmospheric effluent sources. However, bay-wide sedimentary denitrification loss 63% potentially recyclable N. This fraction higher many coastal carbon loading. Denitrification efficiency apparently not enhanced benthic productivity nor bio-irrigation. The rate bio-irrigation negatively correlated efficiency. Bio-irrigation studied using radon-222 CsCl spike injection measurements. Radon fluxes from sediments Bay over diffusive 3–16 times. modelled Cs positively radon enhancement results. Both methods identify have particularly high non-diffusive pore-water exchange.