The model study aims at the assessment of effects of mining activities of manganese nodules in the deep-sea. A Lagrangian transport model is applied on a global scale to estimate the possible temporal and spatial scales of the dispersion of released tailings. The simulations take into account variations of the sediment properties, of the water depth of the release and of the hydrodynamical regime. This is necessary since the current system in the area of interest, the German mining claim in the eastern equatorial Pacific, is characterized by high interannual variations.
Future mining of manganese nodules in the deep-sea should be carried out with the least negative impact on the ecosystem. This can only be achieved when the knowledge on the temporal and spatial scales of the involved processes as well as of the possible impact of mining activities has improved. The investigations of the interdisciplinary project ATESEPP (Auswirkungen technischer Eingriffe auf das Ökosystem der Tiefsee im Süd-Ost-Pazifik vor Peru meaning Effects of technical interference in the ecosystem of the deep-sea in the south easterly Pacific near Peru) in the framework of TUSCH (Tiefseeumweltschutz meaning Deep-sea environmental protection) focussed on the benthic ecosystem. The location of the investigations was an area in the German mining claim in the eastern equatorial Pacific where a mining-like disturbance was set. Within this framework modelling efforts were made on meso- and macroscale impacts of the stirred-up sediments and tailings (Zielke et aI, 1995, Jankowski et aI, 1996, Segschneider and Siindermann, 1997, 1998). Since the scales of possible effects are still unknown, a modelling approach was made on the global domain in order to estimate the dispersion of substances which are released during mining activities. Therefore, the dimension of the affected area and the duration of the effects are to be determined.