Title: mpact of Arenicola marina on bacteria in intertidal sediments
Abstract:On intertidal flats of the North Frisian Wadden Sea, total abundance and biomass of bacteria were examined at 6 sites in the particle transport system of Arenicola marina burrows.Both bacterial abunda...On intertidal flats of the North Frisian Wadden Sea, total abundance and biomass of bacteria were examined at 6 sites in the particle transport system of Arenicola marina burrows.Both bacterial abundance and biomass showed maxima on the input side, with distinctive peaks in the polychaete's foregut (oesophagus), and declined on the egestive side (hindgut and fecal casts) by 70 % .Cell sizes did not differ significantly among sampling sites In feeding experiments using fluorochromelabelled (killed) bacteria and indigestible fluorescent particles as a reference standard, disappearance rates of total bacterial biomass were 80 to 90%.Gut extracts showed lysozyme activity.Peaks of bacterial densities in sediment samples from the foregut region that did not appear in the feeding experiments with killed bacteria suggest 'gardening' Despite high variances, decreasing viable counts of bacteria on nutnent agar noted between paired foregut and h~ndgut samples indicated selective sumvalRead More