Biodegradation and Carbon Flow Based on Kelp (Ecklonia maxima) Debris in a Sandy Beach Microcosm

Abstract

Primary decon~position of intertidally stranded kelp Ecklonia maxima in a mixed substrate microcosm is effected by bacteria rather than by fungi, which are generally reported to be responsible for the initial decomposition phases of debris in other habitats. Initial colonisation by cocci along the junctions of epidermal cell walls leads to lysis and release of cell contents. Lysed cells are then colonised by bacterial rods. High concentrations of leachates, reaching 5640 mg carbon 1-' subsequently appear beneath the decomposing kelp. Over 90 % of the carbon in these leachates is utilised by bacteria during drainage through a strip of sand 1 m long, 50 cm wide and 12 cm deep,