title: Role of sulfate reduction versus methanogenesis in terminal carbon flow in polluted intertidal sediment of waimea inlet, nelson, new zealand.
abstract: An investigation of the terminal anaerobic processes occurring in polluted intertidal sediments indicated that terminal carbon flow was mainly mediated by sulfate-reducing organisms in sediments with high sulfate concentrations (>10 mM in the interstitial water) exposed to low loadings of nutrient (equivalent to <10 kg of N . day) and biochemical oxygen demand (<0.7 x 10 kg . day) in effluents from different pollution sources. However, in sediments exposed to high loadings of nutrient (>10 kg of N . day) and biochemical oxygen demand (>0.7 x 10 kg . day), methanogenesis was the major process in the mediation of terminal carbon flow, and sulfate concentrations were low (</=2 mM). The respiratory index [CO(2)/(CO(2) + CH(4))] for [2-C]acetate catabolism, a measure of terminal carbon flow, was >/=0.96 for sediment with high sulfate, but in sediments with sulfate as little as 10 muM in the interstitial water, respiratory index values of </=0.22 were obtained. In the latter sediment, methane production rates as high as 3 mumol . g (dry weight) . h were obtained, and there was a potential for active sulfate reduction.
authors.affiliation: Cawthron Institute, Nelson, New Zealand.
authors.forename: D O
authors.initials: DO
authors.lastname: Mountfort
authors.forename: R A
authors.initials: RA
authors.lastname: Asher