An assessment of sediment toxicity in the River Tyne Estuary, UK by means of bioassays

Abstract

This paper describes an evaluation of the toxicity of contaminated sediments obtained in June 1992 from six intertidal stations on a 25 km stretch of the industrialised River Tyne Estuary in northeast England. The bioassays for toxicity included the amphipod Corophium spp. and the polychaete Arenicola marina whole sediment tests, as well as tests on elutriates with the copepods Tisbe battagliai and Acartia tonsa, the embryo of the oyster Crassostrea gigas, the light-emitting bacterium Photobacterium phosphoreum and the unicellular algae Tetraselmis suecica and Thalassiosira pseudonana. Tisbe battagliai was also tested with pore water samples from some stations. The sediment samples were analysed for a wide range of chemicals. These analyses showed that contaminants were present at particularly high concentrations at one of the stations (River Team confluence), and this was reflected in the results obtained with the wholesediment bioassays. Detailed studies at this station showed that contamination varied markedly over distances of a few metres. On the other hand, the elutriate and pore water tests gave results which were not clearly linked to the distribution of measured contaminants among the six stations. The implications of these results for the use of sediment toxicity bioassays in environmental monitoring are discussed.