Spatiotemporal Variability of Dimethylsulphoniopropionate on a Fringing Coral Reef : The Role of Reefal Carbonate Chemistry and Environmental Variability

• Published in: PLoS ONE
• Main Authors: Burdett, Heidi L., Donohue, Penelope J. C., Hatton, Angela D., Alwany, Magdy A., Kamenos, Nicholas A.
• Other Authors: University of St Andrews. Earth and Environmental Sciences
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2013
• Subjects: Great Barrier Reef; Ocean acidification; Marine macroalgae; Elevated CO2; Algae; DMSP; Seawater; Calcification; Dimethylsufide; Impacts; Q Science; SDG 14 - Life Below Water; Q
• Online Access: http://hdl.handle.net/10023/4136; https://doi.org/10.1371/journal.pone.0064651

This research was financially supported by a NERC studentship (NE/H525303/1) to HB, a University of Glasgow Mobility Scholarship to HB and PD and a Royal Society of Edinburgh/Scottish Government Fellowship (RSE 48701/1) and Carnegie Trust for the Universities of Scotland grant to NK. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Oceanic pH is projected to decrease by up to 0.5 units by 2100 (a process known as ocean acidification, OA), reducing the calcium carbonate saturation state of the oceans. The coastal ocean is expected to experience periods of even lower carbonate saturation state because of the inherent natural variability of coastal habitats. Thus, in order to accurately project the impact of OA on the coastal ocean, we must first understand its natural variability. The production of dimethylsulphoniopropionate (DMSP) by marine algae and the release of DMSP's breakdown product dimethylsulphide (DMS) are often related to environmental stress. This study investigated the spatiotemporal response of tropical macroalgae (Padina sp., Amphiroa sp. and Turbinaria sp.) and the overlying water column to natural changes in reefal carbonate chemistry. We compared macroalgal intracellular DMSP and water column DMSP+DMS concentrations between the environmentally stable reef crest and environmentally variable reef flat of the fringing Suleman Reef, Egypt, over 45-hour sampling periods. Similar diel patterns were observed throughout: maximum intracellular DMSP and water column DMS/P concentrations were observed at night, coinciding with the time of lowest carbonate saturation state. Spatially, water column DMS/P concentrations were highest over areas dominated by seagrass and macroalgae (dissolved DMS/P) and phytoplankton (particulate DMS/P) rather than corals. This research suggests that macroalgae may use DMSP to maintain metabolic function during periods of low carbonate saturation state. In the reef system, seagrass and macroalgae ...