Effects of Barcelona harbor sediments in biological responses of the polychaete Capitella teleta.

Marine ecosystems are increasingly exposed to a multitude of anthropogenic contaminants. Harbor environments are permanently subjected to such contaminants and bottom sediments are considered as the final repository. Filter-feeding and burrowing organisms, such as some polychaete communities, are among the most exposed organisms. This study aimed to assess the toxicity of Barcelona harbor sediments to the polychaete Capitella teleta by assessing and linking individual-level responses such as body weight (growth) and egestion rate (feeding) with subcellular-level responses including antioxidant (catalase and superoxide dismutase) and neurotransmission related (acetyl cholinesterase) enzyme activities. Sediments were collected from three different locations of the Barcelona (Spain) harbor with a positive gradient of metallic and organochlorine pollution from the mouth of the harbor towards the innermost zone. Sub-cellular and individual behavior of C. teleta exposed to Barcelona harbor sediments allowed the discrimination of toxic responses across sediments. Behavior responses were better correlated to chemical contamination than those of biomarkers. Harbor sediments produced neurotoxicity, promoted oxidative stress and reduced egestion and growth rates in exposed worms. These results indicate that biological responses of C. teleta worm can be used as early-warning tools to assess pollution effects on marine soft-bottom macrobenthonic communities.