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. Antioxidant stress related biomarkers (glutathione S−transferase, superoxide dismutase, catalase, malondialdehyde) in D. aff. meteor tissues were used to evaluate the degree of cellular stress induced by exposure to PMS and quartz particles at times 0 and 13 days in all treatments and from the control and quartz treatments also at time 27 days of the experiment
