IMIS

Sediment cores from shallow, intertidal sites 20 were collected at low tide by manual insertion of plastic core liners (different types were used at different locations; inner diameter range 36 - 60 mm). Cores from deeper areas were sampled shipboard using a gravity core sampler (60 mm internal diameter; UWITEC (Austria) ). The time between sampling and measurement was kept as short as possible, and sediment core analysis (microsensor depth profiling) was always performed within 12 hours of core sampling. During this period, the overlying water of the subtidal sediment cores was kept oxygenated by air bubbling or by submerging the sediment cores into a large water bath filled with in situ bottom water.