During Sonne cruise SO242-2 six enclosure corrals (30*30 cm) were deployed in undisturbed sediment at the southern reference site of the DISCOL experimental area using ROV Kiel 6000 (GEOMAR). Artificial sediment was incubated at 2°C in filtered seawater (sediment effect) or in filtered seawater spiked with copper (copper effect; 1, 5, 10, or 20 mg Cu L-1) for 72 h prior to deployment and subsequently added on top of the deep-sea sediment inside the corrals. After approx. 94h of in-situ incubation, push cores (7.4 cm inner diameter) were taken inside the corrals and sliced in different depth layers (artificial sediment layer, 0-1 cm, 1-2 cm and 2-5 cm). Samples were fixed in formaldehyde and meiofauna was analysed in the lab of the Marine Biology group at Ghent university.

Experimental treatment:NS=no addition of sediment (control)UnC=addition of non-copper-spiked sediment (control)C1=1 mg/L CUSO4C2=5 mg/L CUSO4C3=10 mg/L CUSO4C4=20 mg/L CUSO4