Seawater pH predicted for the year 2100 affects the metabolic response to feeding in Copepodites of the Arctic Copepod Calanus glacialis, supplement to: Thor, Peter; Bailey, Allison; Halsband, Claudia; Guscelli, Ella; Gorokhova, Elena; Fransson, Agneta (2016): Seawater pH Predicted for the Year 2100 Affects the Metabolic Response to Feeding in Copepodites of the Arctic Copepod Calanus glacialis. PLoS ONE, 11(12), e0168735

• Main Authors: Thor, Peter, Bailey, Allison, Halsband, Claudia, Guscelli, Ella, Gorokhova, Elena, Fransson, Agneta
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2016
• Subjects: Animalia; Arctic; Arthropoda; Bottles or small containers/Aquaria <20 L; Calanus glacialis; Coast and continental shelf; Laboratory experiment; Other; Pelagos; Polar; Respiration; Single species; Zooplankton; Type; Species; Registration number of species; Uniform resource locator/link to reference; Experiment; Treatment; Metabolic rate of carbon per carbon mass; RNA/DNA ratio; DNA content per individual; Temperature, water; Temperature, water, standard deviation; Salinity; Salinity, standard deviation; Alkalinity, total; Alkalinity, total, standard deviation; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; pH; pH, standard deviation; Partial pressure of carbon dioxide water at sea surface temperature wet air; Partial pressure of carbon dioxide, standard deviation; Carbonate system computation flag; Carbon dioxide; Fugacity of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Aragonite saturation state; Calcite saturation state; Potentiometric titration; Coulometric titration; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. 2010; Ocean Acidification International Coordination Centre OA-ICC; Agneta; Kongsfjord; Arctic copepod; Kongsfjord*; Ocean acidification; Copepods; Spitsbergen
• Online Access: https://dx.doi.org/10.1594/pangaea.874790; https://doi.pangaea.de/10.1594/PANGAEA.874790

Widespread ocean acidification (OA) is transforming the chemistry of the global ocean, and the Arctic is recognised as a region where the earliest and strongest impacts of OA are expected. In the present study, metabolic effects of OA and its interaction with food availability was investigated in Calanus glacialis from the Kongsfjord, West Spitsbergen. We measured metabolic rates and RNA/DNA ratios (an indicator of biosynthesis) concurrently in fed and unfed individuals of copepodite stages CII-CIII and CV subjected to two different pH levels representative of present day and the "business as usual" IPCC scenario (RCP8.5) prediction for the year 2100. The copepods responded more strongly to changes in food level than to decreasing pH, both with respect to metabolic rate and RNA/DNA ratio. However, significant interactions between effects of pH and food level showed that effects of pH and food level act in synergy in copepodites of C. glacialis. While metabolic rates in copepodites stage CII-CIII increased by 78% as a response to food under present day conditions (high pH), the increase was 195% in CII-CIIIs kept at low pH-a 2.5 times greater increase. This interaction was absent for RNA/DNA, so the increase in metabolic rates were clearly not a reaction to changing biosynthesis at low pH per se but rather a reaction to increased metabolic costs per unit of biosynthesis. Interestingly, we did not observe this difference in costs of growth in stage CV. A 2.5 times increase in metabolic costs of growth will leave the copepodites with much less energy for growth. This may infer significant changes to the C. glacialis population during future OA. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2016) 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 2017-04-21.