We report the results of an aquaria-based experiment testing the effects of suspended particles generated during potential mining activities, on a common habitat-building coral species in the Azores, Dentomuricea aff. meteor. Coral fragments were maintained in 10-L aquaria and exposed to three experimental treatments for a period of four weeks at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores): (1) control conditions (no added sediments); (2) suspended polymetallic sulphide (PMS) particles; (3) suspended quartz particles. Integrated measurements of coral respiration and ammonium release rates were carried out by closed-chamber incubation in cylindrical acrylic chambers on days 0, 13 and 27 of the experiment using an oxygen meter Fibox4 with a PSt3 sensor (PreSens, Germany). Coral respiration and excretion rates were normalized to the coral skeletal surface area
