title: Air exposure of coral is a significant source of dimethylsulfide (DMS) to the atmosphere.
abstract: Corals are prolific producers of dimethylsulfoniopropionate (DMSP). High atmospheric concentrations of the DMSP breakdown product dimethylsulfide (DMS) have been linked to coral reefs during low tides. DMS is a potentially key sulfur source to the tropical atmosphere, but DMS emission from corals during tidal exposure is not well quantified. Here we show that gas phase DMS concentrations (DMSgas) increased by an order of magnitude when three Indo-Pacific corals were exposed to air in laboratory experiments. Upon re-submersion, an additional rapid rise in DMSgaswas observed, reflecting increased production by the coral and/or dissolution of DMS-rich mucus formed by the coral during air exposure. Depletion in DMS following re-submersion was likely due to biologically-driven conversion of DMS to dimethylsulfoxide (DMSO). Fast Repetition Rate fluorometry showed downregulated photosynthesis during air exposure but rapid recovery upon re-submersion, suggesting that DMS enhances coral tolerance to oxidative stress during a process that can induce photoinhibition. We estimate that DMS emission from exposed coral reefs may be comparable in magnitude to emissions from other marine DMS hotspots. Coral DMS emission likely comprises a regular and significant source of sulfur to the tropical marine atmosphere, which is currently unrecognised in global DMS emission estimates and Earth System Models.
authors: Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, United Kingdom.
authors: Frances E
authors: FE
authors: Hopkins
authors: Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, United Kingdom.
authors: Thomas G
authors: TG
authors: Bell
authors: Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, United Kingdom.
authors: Mingxi
authors: M
authors: Yang
authors: School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, United Kingdom.|Climate Change Research Cluster, University of Technology Sydney, PO Box 123, Broadway NSW 2007, Australia.
authors: David J
authors: DJ
authors: Suggett
authors: School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, United Kingdom.
authors: Michael
authors: M
authors: Steinke
mesh_terms: D000388:Air; D000818:Animals; D037421:Anthozoa / Q000378:metabolism*; D002849:Chromatography, Gas; D004121:Dimethyl Sulfoxide / Q000737:chemistry / Q000378:metabolism; D005470:Fluorometry; D005740:Gases / Q000737:chemistry; D012623:Seawater / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry / Q000378:metabolism*; D013452:Sulfonium Compounds / Q000737:chemistry / Q000378:metabolism
chemical_list: D005740:Gases; D013440:Sulfides; D013452:Sulfonium Compounds; C068078:dimethylpropiothetin; C004784:dimethyl sulfide; D004121:Dimethyl Sulfoxide