The seasonal dynamics of benthic (micro) organisms and extracellular carbohydrates in an intertidal mudflat and their effect on the concentration of suspended sediment

摘要: The Ems-Dollard estuary, situated in the north of Netherlands near to German border, is covered for a large part by intertidal flats. Currents and wind- induced waves exert shear stress on these flats, resulting resuspension sediment. Fluctuations suspended sediment concentration Dollard are strongly affected erosion due wind-induced settling during calm weather conditions. However it believed that benthic processes influence amount can be resuspended from Therefore above Heringsplaat, an flat was measured two seasons related dominant biological features. benthos abiotic characteristics were monitored 1995 till 1997, at stations. At both stations peak chlorophyll-α found spring, caused diatom bloom. Meiobenthos dominated nematodes, macrobenthos polychaete Marenzelleria viridis amphipod Corophium volutator. seasonal pattern studied most intensively 1996. Monthly sampling done Heringsplaat. with ice March. This period followed clear water phase spring increase silt content edge During this carbohydrate concentration. secretion stabilized finally resulted stable mat end two-centimeter thick layer silt. June high nematodes volutator found. Nematode density about 5000 ind per 10 cm 2 July reached almost 100.000 m . population decreased rapidly June. It assumed grazing pressure Corophium. reduced increased bioturbation activity stability. surface Heringsplaat same time turbidity column increased.