Bacterial numbers and activity, microalgal biomass and productivity, and meiofaunal distribution in sediments naturally contaminated with biogenic bromophenols

Abstract

Sediment cores were collected inside and outside of a bed of bromophenol-producing marine polychaete, Notomastus lobatus. No significant differences were found between microbial parameters. Integrated 6 cm cores taken adjacent to N. lobatus burrows contained 1.2 × 109 bacteia ml-1. Cell numbers were similar at control sites within the bed, but away from burrows, and not significantly different from cell numbers (1.0 × 109 cells ml-1) at a nearby site. [3H]-acetate net assimilation rates were 12.7 ± 5.0 pmol ml-1 h-1 adjacent to burrows and 11.9 ± 1.4 pmol ml-1 h-1 in non-burrow control cores. Microalgal biomass was 20.1 ± 1.2 mg chl a m-2 adjacent to burrows and 24.3 ± 1.0 mg chl a m-2 in non-burrow control cores. Microalgal production was 4.17 ± 0.31 mmol O2 m-2 h-1 near burrows and 5.84 ± 0.97 mmol O2 m-2 h-1 in controls. Distribution of bacteria, microalgae, and meiofauna showed no consistent effects of proximity to the worm burrows. -from Authors