Photosynthetic activity buffers ocean acidification in seagrass meadows, supplement to: Hendriks, Iris; Olsen, Ylva; Ramajo, L; Basso, L; Steckbauer, Alexandra; Moore, T S; Howard, J; Duarte, Carlos Manuel (2014): Photosynthetic activity buffers ocean acidification in seagrass meadows. Biogeosciences, 11(2), 333-346

• Main Authors: Hendriks, Iris, Olsen, Ylva, Ramajo, L, Basso, L, Steckbauer, Alexandra, Moore, T S, Howard, J, Duarte, Carlos Manuel
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2014
• Subjects: Benthos; Biomass/Abundance/Elemental composition; Coast and continental shelf; Field observation; Growth/Morphology; Macroalgae; Mediterranean Sea; Plantae; Posidonia oceanica; Single species; Temperate; Tracheophyta; Species; Time point, descriptive; Season; Station label; Site; Temperature, water; Temperature, water, standard deviation; Illuminance; Illuminance, standard deviation; Shoot density; Shoot density, standard error; Biomass; Leaf area index; Calcium carbonate, inorganic; Oxygen; Time; Flow velocity, water; Flow velocity, water, standard error; pH; Aragonite saturation state; Partial pressure of carbon dioxide water at sea surface temperature wet air; Carbon, inorganic, dissolved; Salinity; Salinity, standard deviation; Carbonate system computation flag; Carbon dioxide; Fugacity of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Alkalinity, total; Calcite saturation state; Potentiometric; Pyrheliometer, Eppley, NIP, SN 16523E6, WRMC No. 31296; Calculated using seacarb after Nisumaa et al. 2010; Mediterranean Sea Acidification in a Changing Climate MedSeA; Ocean Acidification International Coordination Centre OA-ICC; Basso; Duarte; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.834083; https://doi.pangaea.de/10.1594/PANGAEA.834083

Macrophytes growing in shallow coastal zones characterised by intense metabolic activity have the capacity to modify pH within their canopy and beyond. We observed diel pH changes in shallow (5-12 m) seagrass (Posidonia oceanica) meadows spanning 0.06 pH units in September to 0.24 units in June. The carbonate system (pH, DIC, and aragonite saturation state (omega Ar)) and O2 within the meadows displayed strong diel variability driven by primary productivity, and changes in chemistry were related to structural parameters of the meadow, in particular, the leaf surface area available for photosynthesis (LAI). LAI was positively correlated to mean, max and range pHNBS and max and range omega Ar. In June, vertical mixing (as Turbulent Kinetic Energy) influenced max and min omega Ar, while in September there was no effect of hydrodynamics on the carbonate system within the canopy. Max and range omega Ar within the meadow showed a positive trend with the calcium carbonate load of the leaves, pointing to a possible link between structural parameters, omega Ar and carbonate deposition. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Lavigne et al, 2014) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation is 2014-07-16.