This dataset was collated from surveys in the west side of Vavvaru Island, Lhaviyani Atoll, Maldives, to examine whether corals have the capacity to create their own stable habitat through free-living stabilisation. The data were collected during March 2015 as a series of triplicate 25 m x 2 m transects parallel to shore, at three locations on the reef flat: near (70 m from the shore), mid (140 m from the shore) and far (210 m from the shore). All locations were at similar depths of 1 m. Along each transect the number and size of all coralliths and total number of non-free living individuals were recorded, alongside with several environmental parameters (Water Temperature, Photosynthetically Available Radiation (PAR), Total Alkalinity, Dissolved Inorganic Carbon and Dissolved Oxygen). Abundance and size of coralliths was recorded through non-invasive techniques and the environmental parameters were obtained through multiple instruments: Fluorometer, Oxygen sensor, spectrophotometry, Titration and a PAR logger. The work was supported by an Independent Research Fellowship from NERC to Sebastian Hennige (NE/K009028/1, NE/K009028/2), an Independent Research Fellowship from the Marine Alliance for Science and Technology for Scotland to Heidi Burnett, an Independent Research Fellowship from the Royal Society of Edinburgh / Scottish Government (RSE 48701/1) and NERC (NE/H010025) to Nick Kamenos, a Gilchrist Fieldwork Award to Heidi Burnett, Sebastian Hennige and Nick Kamenos by the Gilchrist Educational Trust, administered by the Royal Geographical Society (with the Institute of British Geographers), and a Research Incentive Grant from the Carnegie Trust for the Universities of Scotland to Heidi Burnett, Sebastian Hennige and Nick Kamenos (grant number 70013). Field sampling was under permission from the Maldives Ministry of Fisheries and Agriculture ((OTHR) 30-D/lNDIV/2015).

Dimethylsulphoniopropionate (DMSP), and its breakdown product dimethylsulphide (DMS), are putative antioxidants that may be accumulated by invertebrates via their food or symbionts; recent research suggests that some invertebrates may also be able to synthesise DMSP. This dataset is the first to provide information on the impact of high temperature (12degC) and high CO2 (817 ppm) on intracellular DMSP in the cold water coral Lophelia pertusa from the Mingulay Reef Complex, Scotland (56deg49'N, 07deg23'W). The experiment was conducted during the 'Changing Oceans Expedition' in June 2012, aboard the Royal Research Ship James Cook (cruise JC073). Coral colonies were obtained using the Holland-1 Remotely Operated Vehicle (ROV) 180 m below chart datum at the Mingulay Reef Complex and maintained for 10 days in one of four treatments (control, high temperature, high CO2, high temperature+CO2). Samples for coral intracellular DMSP and mesocosm water DMS+DMSP were fixed on-board and transported to the University of Glasgow for subsequent analysis by gas chromatography.