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

(PET-1119-269679) The effects of Irgarol 1051 on cultured zooxanthellae.

Pettay, T^{1, 2, 3}, DeLorenzo, M¹, Pennington, P¹, Galloway, S¹, Woodley, C^{1, 2}, ¹ NOAA NOS NCCOS Center for Coastal Environmental Health and Biomolecular Research, Charleston, SC, USA² Hollings Marine Laboratory, Charleston, SC, USA³ College of Charleston Grice Marine Biology Program, Charleston, SC, USA

ABSTRACT- Irgarol 1051 is one of several anti-fouling compounds developed in response to the international ban on organotin compounds. Recent reports have indicated Irgarol 1051 contamination of tropical waters and demonstrated negative impacts to whole coral and freshly isolated zooxanthellae (genus Symbiodinium) at environmentally relevant concentrations. In this study the effects of Irgarol 1051 on growth rate, ¹⁴C incorporation, and chlorophyll fluorescence of six cultures of Symbiodinium sp. were determined. The cultures are genetically different strains isolated from various cnidarian hosts and represent four clades from within the genus. Preliminary data indicate no significant difference in response to Irgarol 1051 exposure among the cultures. Irgarol exposure resulted in a significant reduction of F_v/F_m at concentrations as low as 0.05 g/L (24h); ¹⁴C incorporation as low as 3.75 g/L (24h), and 0.03 g/L (96h); and growth rate as low as 7.5 g/L (24h), and 0.03 g/L (96h). Although not all short term exposure (24 h) results occurred at environmentally relevant concentrations, the effects due to longer exposures (96h) occurred within the range of concentrations commonly reported for coastal marine waters. This study focused specifically on one half of the coral/algal symbiosis, but any deleterious effects on one component could have dramatic effects on the symbiosis as a whole. The results determined in this study are very similar to previously published results for Irgarol 1051 exposures using whole coral and freshly isolated zooxanthellae. These similar results indicate the possibility of using cultured Symbiodinium as a non-invasive method for conducting coral toxicity experiments.

Key words: Irgarol 1051, Zooxanthellae, Coral, Anti-fouling