Stazione Zoologica 1 article published in JoVE Environment Ecotoxicological Method with Marine Bacteria Vibrio anguillarum to Evaluate the Acute Toxicity of Environmental Contaminants Alice Rotini1,2, Loredana Manfra1,3, Filippo Spanu2, Marco Pisapia1, Anna Maria Cicero1, Luciana Migliore2 1Institute for Environmental Protection and Research (ISPRA), Rome (Italy), 2Department of Biology, Tor Vergata University, Rome (Italy), 3Department of Biology and Evolution of Marine Organisms, Stazione Zoologica, Anton Dohrn, Naples (Italy) This work describes a new protocol to assess the ecotoxicity of pollutants, including emerging contaminants such as nanomaterials, using the marine bacterium Vibrio anguillarum. This method allows for the determination of the LC50, or mortality, the concentration that causes a 50% decrease in bacteria culturability, after a 6 h exposure.