The Effects of PAH Contamination and Grazing on the Abundance and Composition of Microphytobenthos in Salt Marsh Sediments (Pass Fourchon, LA, U.S.A.): II: The Use of Plant Pigments as Biomarkers

摘要: Abstract A field study was conducted in 1996 and 1997 that examined effects of temporal spatial variability polycyclic aromatic hydrocarbons (PAHs), macro-epifaunal abundance, dissolved inorganic nutrients on the abundance composition microphytobenthos salt marsh sediments Pass Fourchon, LA (U.S.A.). Plant pigment biomarkers were used to monitor seasonal patterns benthic microalgal across a PAH contamination gradient created by past produced-water pumping. The microphytobenthic community at Fourchon primarily composed diatoms cyanobacteria, as indicated carotenoid fucoxanthin zeaxanthin, respectively. Microphytobenthic showed no consistent pattern variation stations or seasons; chlorophyll concentrations generally ranged from 0·2 15·9 μg g dry sediment −1 . Significantly higher nitrogen (DIN) observed porewaters highly contaminated (high PAHs) station; ammonium had highest range (160 8500 μM Station 1a). Higher DIN likely due rapid remineralization detritus station. response enhanced availability hindered toxicity and/or macro- meiobenthic grazing effects. In September each year, significant increases total concentration surface site (Station Examination isomer ratios indicates this physical mixing events (i.e. storms) not changes inputs preferential certain PAHs.