Organic pollution and its effects: a short-term transplant experiment to assess the ability of biological endpoints to detect change in a soft sediment environment

Abstract

A wide variety of endpoints or metrics are commonly employed in pollution monitoring situations but, to date, there have been very few experimental field studies aimed at assessing links between a putative pollutant and established soft sediment assemblages. We carried out a manipula- tive field experiment whereby intact assemblages were transplanted from control areas to sites adja- cent to drains discharging secondary treated sewage effluent at 3 intertidal outfall locations in Port Phillip Bay, Victoria, Australia. We found that the ability of different measures to detect impacts var- ied, although multivariate methods were able to discriminate the effects of treatment, and population level measures tended to be more sensitive than assemblage level measures of abundance, biomass and diversity. Integrated measures, such as average individual biomass, were found to provide a sen- sitive detection tool plus an insight into the biological consequences of observed changes. We con- sider our findings in the light of conceptual models of pollution-induced change in soft sediment assemblages.