Can corals form aerosol particles through volatile sulphur compound emissions?

Acropora dominated coral reefs are a substantial source of atmospheric dimethylsulphide (DMSa), one of the most abundant reduced sulphur gases present in the marine boundary layer. DMS is believed to act as a climate regulator of solar radiation and sea surface temperatures through the formation of non-sea-salt sulphate aerosols and cloud condensation nuclei (CCN), although this regulation has not yet been demonstrated. A bubbling chamber experiment was conducted on coral reef seawater containing a branch of Acropora pulchra, to investigate whether the coral-generated DMSa could be oxidised to non-seasalt sulphate aerosols under treatment with UV light and O3. Results indicated that A. pulchra produced significant amounts of dimethylsulphoniopropionate (DMSP) and dissolved DMS although emissions of DMSa in the chamber headspace were reduced by the presence of the coral, probably as a result of antioxidant activity in the coral tissue. Significant amounts of carbon disulphide (CS2) and ethanethiol (ESH), other sulphur gases that could be involved in CCN formation, were also indicated in the bubbling chamber, most likely from coral production. A decrease in DMSa and CS2 in the presence of UV light and O3 followed by an occurrence of freshly nucleated nanoparticle