Bioaccumulation, oxidative stress and cellular damage in the intertidal gastropod Bembicium nanum exposed to a metal contamination gradient

Abstract

The high concentration of population and industry in coastal areas leads to contamination. In situ biomonitors provide a reliable and cost-effective means of assessing the effects of contamination. Rigorous assessment of biomonitors is required to establish links between biomarker measurements and contamination in the environment. The aims of the present study were to assess the effects of metal contamination on the intertidal gastropod Bembicium nanum and to validate biomarkers for use in this species. B. nanum was sampled from a metal contamination gradient emanating from Port Kembla (NSW, Australia). Tissue metal concentrations were related to the condition of organisms as assessed using the biomarkers total antioxidant capacity, lipid peroxidation and lysosomal destabilisation. Total tissue metal concentrations were highest in Port Kembla organisms, with copper contributing 56% of metals measured in organisms from this site. B. nanum from Port Kembla also had significantly higher lysosomal destabilisation, being 36% higher than Kiama and 80% higher than Shellharbour over the combined sampling times. Lysosomal destabilisation was related to total tissue metal concentration and Cu tissue concentration. The results of the present study establish B. nanum as a bioindicator of metal contamination, with effects primarily relating to copper, and support previous work on the species as an effective biomonitor of bioavailable metal.