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) and those were sliced in different depth layers (added substrate layer, 0-1 cm,1-2 cm and 2-5 cm sediment depth). Samples were fixed in formaldehyde and meiofauna was analysed in the lab of the Marine Biology group at Ghent university.

AS=added substrateSD=substrate addition treatment