title: A short-term sublethal in situ toxicity assay with Hediste diversicolor (Polychaeta) for estuarine sediments based on postexposure feeding.
abstract: This study evaluated a short-term sublethal endpoint for in situ toxicity assays for estuarine sediments, based on postexposure feeding of the polychaete Hediste (Nereis) diversicolor Müller. A method for precisely quantifying postexposure feeding rates of H. diversicolor was established under laboratory conditions using Artemia franciscana Kellog nauplii. The sensitivity of the postexposure feeding response to copper was investigated by comparing postexposure feeding rates to growth and lethality. The 48-h and 96-h median lethal concentration (LC50) of copper were 241 and 125 microg/L, respectively, whereas the 48-h median inhibitory concentration (IC50) for postexposure feeding and the 20-d IC50 for growth were 52 and 25 microg/L of copper, respectively. The influence of different exposure conditions (substrate, temperature, salinity, food availability, and light) on H. diversicolor postexposure feeding was assessed; temperature and salinity were found to influence significantly postexposure feeding. The effectiveness of the proposed in situ assay was investigated by deploying it at two reference and six contaminated Portuguese estuaries. A 48-h exposure period was followed by a 1-h postexposure feeding period. High organism recoveries (89-100%) were obtained. Postexposure feeding was depressed significantly (17-90%) at all contaminated sites relatively to reference sites. The proposed in situ assay with H. diversicolor was shown to be a potential useful tool for estuarine sediment toxicity testing.
authors.affiliation: Instituto de Ciências Biomédicas de Abel Salazar, Departamento de Estudos de Populações, Largo Abel Salazar 2, 4099-003 Porto, Portugal.
authors.forename: Susana Maria
authors.initials: SM
authors.lastname: Moreira
authors.forename: Matilde
authors.initials: M
authors.lastname: Moreira-Santos
authors.forename: Lúcia
authors.initials: L
authors.lastname: Guilhermino
authors.forename: Rui
authors.initials: R
authors.lastname: Ribeiro
mesh_terms: D000818:Animals; D019015:Geologic Sediments / Q000737:chemistry*; D011077:Polychaeta / Q000187:drug effects*; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical