W10 PM Environmental Interactions of Marine Antifoulants
Wednesday, 16 November 2005: 1:50 PM - 5:30 PM in 341-342

(BAU-1118-674375) Stenoprohiluric Coatings - The Dawn of Sustainable Nontoxic Marine Antifoulants.

Guritza, D¹, Baummer, J², Kiefer, L³, ¹ Natural Science Technologies, Chagrin Falls, OH, USA² EA Engineering Science and Technology, Sparks, MD, USA³ MeadWestvaco Corporation, Laurel, MD, USA

ABSTRACT- Traditional cuprous oxide based marine anitifoulant coatings rely on an ablative release of toxins to prevent hard fouling on coated surfaces. Many traditional coatings contain booster biocides (herbicides and molluscicidies) that add additional toxic impacts to enhance efficacy, due to the inherent limits of cuprous oxides in managing different fouling conditions. The coating evaluated in this study takes a revolutionary approach to prevent fouling by creating and sustaining a biofilm that utilizes metallic copper in a unique resin system to create an environment that inhibits settling of undesirable organisms. There were two objectives for this study: 1) evaluate the acute toxicity of field exposed and sterile panels to three marine organisms, the opossum shrimp (Americamysis bahia), the silverside minnow (Menidia beryllina) and the sheepshead minnow (Cyprinodon variegatus) and 2) to determine the release rate of copper from field exposed panels. Acute toxicity and copper release from EcoClad™ coating formulation (resin + copper metal) was periodically evaluated from 0 to 297 days. Resin-only panels and copper metal panels (CDA #110) (negative and positive copper controls, respectively) were evaluated for up to 201 days. Sterile panels, immersed in laboratory sterile artificial seawater, were evaluated for acute toxicity and copper release after 14, 63 and 126 days of exposure. Acute toxicity tests completed were 96-hour screening or LC50 assays. Copper release rates were determined using a method derived from the standard ASTM method for measuring copper release from antifoulant coatings. The EcoClad™ formulation was nontoxic to A.bahia and C. variegatus with 96-hour LC50 values >100 percent sample after 13 days immersionin situ. Copper release rates were <10g/cm²/day. The resin-only panels were nontoxic (both in situ and sterile) throughout the test period. No copper release was detected. Copper metal panels (both in situ and sterile) were toxic to and A. bahia and M. beryllina throughout the test period. The copper release rates from the copper metal panels were several orders of magnitude higher than the copper release rates from EcoClad™ (in situ or sterile conditions).

Key words: Marine coatings, acute toxicity, Americamysis bahia, Cyprinodon variegatus