Interlaboratory assessment of marine bioassays to evaluate the environmental quality of coastal sediments in Spain. I. Exercise description and sediment quality

Abstract

 The results of an interlaboratory assessment made to evaluate the use of different bioassays for sediment quality characterization for a regulatory purpose are presented. The objective of the study was to determine the main differences among sediment bioassays conducted at different laboratories and to evaluate how this can influence dredged material management. The exercise consisted of two parts. During Phase I, six dredged sediment samples from different Spanish ports (Barcelona, Bilbao, Cádiz, Cartagena and Huelva) were distributed to different laboratories where they were applied a screening test for initial toxicity evaluation, a test for elutriates and two solid-phase bioassays. In Phase II, six new sediment samples (from the ports of Algeciras, Bilbao, Cádiz and Huelva) were tested to re-evaluate some bioassays for which different interfering factors were identified during the first phase. The chemical characterization results for Phase I showed high concentrations of some compounds in all the samples except one, which could be considered uncontaminated, while those for Phase II showed high concentrations in most sediments of some metallic compounds, mainly Cu, Hg and As, and to a lesser extent Cd, and of the total polychlorinated biphenyl congeners analyzed. According to Spanish guidelines for dredged material management, only one of the six samples assessed in each phase of the exercise would be suitable for open water disposal.