Experiment: Competition between calcifying and noncalcifying temperate marine macroalgae under elevated CO2 levels, supplement to: Hofmann, Laurie C; Straub, Susanne M; Bischof, Kai (2012): Competition between calcifying and noncalcifying temperate marine macroalgae under elevated CO2 levels. Marine Ecology Progress Series, 464, 89-105

• Main Author: Hofmann, Laurie C
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2012
• Subjects: Benthos; Chondrus crispus; Coast and continental shelf; Community composition and diversity; Containers and aquaria 20-1000 L or < 1 m**2; Corallina officinalis; Derbesia marina; Dumontia incrassata; Entire community; Fucus vesiculosus; Growth/Morphology; Laboratory experiment; North Atlantic; Petalonia sp.; Polysiphonia fucoides; Primary production/Photosynthesis; Respiration; Rocky-shore community; Sargassum muticum; Spongomorpha; Temperate; Ulva Compress; Ulva linza; Species; Treatment; Sample ID; Incubation duration; Light saturation; Maximal electron transport rate, relative; Electron transport rate efficiency; Maximum photochemical quantum yield of photosystem II; Irradiance; Yield; Electron transport rate, relative; Group; Coverage; Simpson's index; Shannon Diversity Index; Gross oxygen evolution, per chlorophyll a; Growth rate; Carbohydrates, solube, in tissue; Carbohydrates, insolube, in tissue; Proteins, in tissue; Carbohydrates, total; Proteins/Carbohydrate ratio; Carbohydrates, insolube/Carbohydrates, solube ratio; Carbohydrates, solube; Carbohydrates, insolube; Protein; Phycoerythrin; Phycocyanin; Chlorophyll a; Chlorophyll b; Respiration rate, oxygen; Salinity; Temperature, water; Alkalinity, total; pH; Phosphate; Silicate; Carbonate system computation flag; Carbon dioxide; Partial pressure of carbon dioxide water at sea surface temperature wet air; Fugacity of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Carbon, inorganic, dissolved; Aragonite saturation state; Calcite saturation state; Calculated using seacarb after Nisumaa et al. 2010; Biological Impacts of Ocean Acidification BIOACID; Ocean Acidification International Coordination Centre OA-ICC; Hofmann; Laurie; Northeast Atlantic; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.830074; https://doi.pangaea.de/10.1594/PANGAEA.830074

Since pre-industrial times, uptake of anthropogenic CO2 by surface ocean waters has caused a documented change of 0.1 pH units. Calcifying organisms are sensitive to elevated CO2 concentrations due to their calcium carbonate skeletons. In temperate rocky intertidal environments, calcifying and noncalcifying macroalgae make up diverse benthic photoautotrophic communities. These communities may change as calcifiers and noncalcifiers respond differently to rising CO2 concentrations. In order to test this hypothesis, we conducted an 86 d mesocosm experiment to investigate the physiological and competitive responses of calcifying and noncalcifying temperate marine macroalgae to 385, 665, and 1486 µatm CO2. We focused on comparing 2 abundant red algae in the Northeast Atlantic: Corallina officinalis (calcifying) and Chondrus crispus (noncalcifying). We found an interactive effect of CO2 concentration and exposure time on growth rates of C. officinalis, and total protein and carbohydrate concentrations in both species. Photosynthetic rates did not show a strong response. Calcification in C. officinalis showed a parabolic response, while skeletal inorganic carbon decreased with increasing CO2. Community structure changed, as Chondrus crispus cover increased in all treatments, while C. officinalis cover decreased in both elevated-CO2 treatments. Photochemical parameters of other species are also presented. Our results suggest that CO2 will alter the competitive strengths of calcifying and noncalcifying temperate benthic macroalgae, resulting in different community structures, unless these species are able to adapt at a rate similar to or faster than the current rate of increasing sea-surface CO2 concentrations. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Lavigne and Gattuso, 2011) 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 by seacarb is 2014-02-11.