Experiment with crushed nodule substrate deposition for eleven days during SONNE cruise SO242/2

During Sonne cruise SO242-2 six steel rings were inserted into undisturbed sediment at the southern reference site of the DISCOL experimental area using ROV Kiel 6000 (GEOMAR). Subsequently, on three of these steel rings a sediment dispenser was deployed to distribute 250 mL of crushed nodule substrate onto the ring surface area resulting in an added layer of approximately 2 cm. The sediment dispensers were left on the steel rings for one night to allow settlement of all particles. After the incubation time of eleven days each steel ring was subsampled with push cores (7.4 cm inner diameter) which were sliced in different depth layers (added substrate layer, 0-1 cm,1-2 cm and 2-5 cm sediment depth). Samples form meiofauna analysis were fixed in formaldehyde while samples for analysis of environmental parameters were stored frozen. In addition to morphological meiofauna analyses, internal copper concentrations were measured in 6 nematodes exposed to the crushed nodule substrate and 12 nematodes from undisturbed sediment by means of µ-X-ray fluorescence.