Context : The bay of Portman and the adjacent shoreline are exposed to one of the most severe cases of sediments contamination by heavy metals of the whole Mediterranean Sea, due to decades of industrial mining activities which took place in the locality from 1951 to 1991. This dataset countains fine scale distribution data for echinoderms collected around the bay of Portman (Murcia, Spain) by the Marine biology laboratory (ULB) in October 2013. The fine scale cartography was realized for both the contamination gradient pattern and the benthic species distribution within the study area. Environmental data are gathered into the Measurement or Facts extension. Most of these data concern heavy metal concentrations (Fe,Cu,Cd,Pb,Zn), for both the total and the finest (particle size <63µm) granulometric fractions of the sediments. Benthic species distribution data are compiled in a DarwinCore archive. The major part of the data are derived from imagery-based identifications on video transects operated with a micro-ROV (VideoRay PRO3 GTO). But it also countains observations made by scuba divers, ad hoc observations, and sampled specimens for the purpose of physiological/ecotoxicological studies.