title: A novel bioassay for evaluating the efficacy of biocides to inhibit settling and early establishment of marine biofilms.
abstract: This paper presents a novel assay that allows a quick and robust assessment of the effects of biocides on the initial settling and establishment of marine photoautotrophic biofilms including the multitude of indigenous fouling organisms. Briefly, biofilms are established in the field, sampled, comminuted and re-settled on clean surfaces, after 72h chlorophyll a is measured as an integrating endpoint to reflect both settling and growth. Eight antifoulants were used to evaluate the assay. Efficacy ranking, based on EC98 values from most to least efficacious compound is: copper pyrithione>TPBP>DCOIT>tolylfluanid>zinc pyrithione>medetomidine>copper (Cu(2+)), while ecotoxicological ranking (based on EC10 values) is irgarol, copper pyrithione>zinc pyrithione>TPBP>tolylfluanid>DCOIT>copper (Cu(2+))>medetomidine. The algaecide irgarol did not cause full inhibition. Instead the inhibition leveled out at 95% effect at 30 nmoll(-)(1), a concentration that was clearly lower than for any other of the tested biocides.
authors.affiliation: University of Gothenburg, Department of Biological and Environmental Sciences, Box 461, SE-405 30 Gothenburg, Sweden. Electronic address: asa.arrhenius@gu.se.
authors.forename: Åsa
authors.initials: Å
authors.lastname: Arrhenius
authors.affiliation: University of Gothenburg, Department of Biological and Environmental Sciences, Box 461, SE-405 30 Gothenburg, Sweden. Electronic address: thomas.backhaus@gu.se.
authors.forename: Thomas
authors.initials: T
authors.lastname: Backhaus
authors.affiliation: University of Gothenburg, Department of Biological and Environmental Sciences, Box 461, SE-405 30 Gothenburg, Sweden. Electronic address: annelie.hilvarsson@gmail.com.
authors.forename: Annelie
authors.initials: A
authors.lastname: Hilvarsson
authors.affiliation: University of Gothenburg, Department of Biological and Environmental Sciences, Box 461, SE-405 30 Gothenburg, Sweden. Electronic address: ida.wendt@gu.se.
authors.forename: Ida
authors.initials: I
authors.lastname: Wendt
authors.affiliation: University of Gdansk, Institute of Oceanography, Al. Pilsudskiego 46, 81-378 Gdynia, Poland. Electronic address: oceazg@univ.gda.pl.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Zgrundo
authors.affiliation: University of Gothenburg, Department of Biological and Environmental Sciences, Box 461, SE-405 30 Gothenburg, Sweden. Electronic address: hans.blanck@gu.se.
authors.forename: Hans
authors.initials: H
authors.lastname: Blanck
mesh_terms: D018441:Biofilms; D057219:Biofouling / Q000517:prevention & control; D001681:Biological Assay / Q000379:methods*; D004202:Disinfectants / Q000737:chemistry / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
chemical_list: D004202:Disinfectants; D014874:Water Pollutants, Chemical
keywords: Antifouling biocides; Ecotoxicology; Microfouling; Periphyton; Photoautotrophic biofilm; Slime