IMPACT OF MACROFAUNA BIOTURBATION ON SMALL-SCALE DISTRIBUTION PATTERNS OF DEEP-SEA MEIOFAUNA: AN EXPERIMENTAL APPROACH
To investigate the impact of small-scale environmental changes on meiobenthic community structure an in situ experiment was carried out to examine and monitor factors controlling deep-sea diversity. In order to understand the complex interactions between the biota (their functioning and diversity) and environmental perturbations/relaxations a free-falling device (bottom lander) equipped with a sediment disturber (SD) has been used. The SD was deployed at the central HAUSGARTEN station (79° 4.48`N 4° 8.58`E, 2493 m water depth). The SD carries three rotating fork-like disturber units able to perturbate the upper sediment layers at chosen time intervals. Three disturbed areas were created by the SD with different disturbance frequencies. A camera system continuously monitors all SD actions. Sediment sampling at the end point of the deployment has been carried out using push-coring devices handled by the ROV Quest ‘4000’. The sediment cores have been sub-sampled to study the effect of controlled sediment perturbations on biochemical sediment parameters as well as on benthic meiofauna communities (with special focus on nematode communities). We will present first results of nematode communities in the upper sediment layers.