CWCs were sampled in situ, after aquaria acclimatization, under experimental conditions simulating an ocean acidification scenario predicted for 2100 (IPCC8.5; pCO2=1,000 atm), and toxic sediment plumes expected from mining of seafloor massive sulphide deposits from an inactive hydrothermal vent field in the Azores. Our first analyses showed that different coral taxa host distinct bacterial communities, and that the coral microbiomes undergo compositional changes after the transition to the aquaria and under OA conditions. Alpha diversity indexes presented a higher microbial diversity after the transition to the aquaria, which become generally higher with the time of captivity and after induced stresses (ocean acidification and deep-sea mining).