Effects of suspended mineral coal dust on the energetic physiology of the Caribbean scallop Argopecten nucleus (Born, 1778)

The effects of increasing concentrations of suspended mineral coal dust on the energetic physiology of the Caribbean scallop Argopecten nucleus were studied, at a concentration range that is environmentally relevant and representative of areas proximate to coal loading and shipping ports. Adult hatchery-produced animals were exposed to different concentrations of coal dust, i.e. 0, 2, 9 and 40 mg L^-1. At increasing concentrations of coal dust, the rates of filtration and pseudofeces production increased, while the rates of ingestion and absorption remained constant. The rates of oxygen consumption and ammonium excretion decreased, as well as the absorption efficiency and the scope for growth. Suspended coal dust particles, at concentrations higher than or equal to 2 mg L^-1, were ingested preferentially over microalgae by A. nucleus, causing reductions in its absorption capability, metabolism and in the amount of energy for growth and reproduction, thus generating physiological stress.