Degradation of antifouling biocides

Abstract

The relative biodegradability in seawater of a number of compounds in current use in antifouling paints viz. Sea-Nine™ 211 antifoulant (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one), Irgarol(R) 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine), diuron (3-(3,4-dichlorophenyl)l-l-dimethylurea), chlorothalonil (tetrachloroisophthalonitrile) and TBTO (tributyltin oxide) was investigated. The disappearance of the each compound from seawater was monitored over 8 w by bioassay using the ship-fouling diatom Amphora coffeaeformis. The results show, that under the test conditions employed, biodegradability ranges from very readily biodegradable (Sea-Nine 211) to non-biodegradable (diuron and Irgarol 1051). The results are discussed in relation to published data on biocide degradation.

Biological fate of Diuron and Sea-nine® 211 and their effect on primary microbial activities in slurries of a contaminated sediment from Venice Lagoon

“…Several bioassays tests assessed the toxicity of Diuron, which is an inhibitor of photosynthesis (Konstantinou and Albanis 2004), while its principal aerobic and anaerobic degradation products, which generally show higher toxicity than the parent compound (Gatidou et al 2007), are a threat to several marine living organisms such as algae, crustacean, fishes, echinoderma, diatoms and mammalians (Tixier et al 2000;Bonnemoy et al 2004;Fernàndez-Alba et al 2002;Okamura et al 2002;Kobayashi and Okamura 2002;Hernando et al 2003;Huang et al 2005;Manzo et al 2006;Bellas et al 2005;Koutsaftis and Aoyama 2007;Silkina et al 2009;Giacomazzi and Cochet 2004); nonetheless, Diuron at 10 mg/L had no significant effect on sea-water aerobic cultivable microorganisms (Harino et al 2005). The recalcitrance of Diuron has been reported in bioassays using a ship-fouling diatom (Callow and Willingham 1996), in laboratory investigations conducted in marine seawater, where Diuron was not photodegraded by sunlight irradiation (Harino et al 2005), its concentration was not reduced over 42 days of aerobic incubation (Thomas et al 2002), nor it was in anaerobic marine sediments, in which half-lives of 14 days were calculated (Thomas et al 2003).…”

Sea‐Nine™ 211 (4,5‐dichloro‐2‐(n‐octyl)‐3(2H)‐isothiazolone) is a Potent Stimulator of Eicosanoid Biosynthesis in the Sea Squirt,Ciona intestinalis(L.)

“…Additionally, this compound provides protection against a range of economically important macrofouling organisms including barnacles, algae, tubeworms, bryozoans and diatoms (Harrington & Willingham, 1993). This broadrange biocidal activity, coupled with a relatively short environmental half life (Shade et ah, 1993;Callow & Willingham, 1996) make it a potentially attractive alternative to organotin (e.g. TBT)-containing coatings, which have been legislated against in many parts of the world.…”

Eco-physiological response of two marine bivalves to acute exposition to commercial Bt-based pesticide

“…While about 80% of the Earth's biodiversity is found in marine environments, the effect of pesticides on marine organisms remains relatively neglected (Callow and Willingham, 1996). Moreover, biomarkers commonly used to assess the impact on nontarget marine organisms are not fully appropriate to explain potential direct and indirect effects.…”