6533b883fe1ef96bd12dd906
RESEARCH PRODUCT
Could the acid-base status of Antarctic sea urchins indicate a better-than-expected resilience to near-future ocean acidification?
Marie CollardChantal De RidderBruno DavidFrank DehairsPhilippe Duboissubject
Ocean Acidification International Coordination Centre (OA-ICC)SalinityNotocidaris gaussensisBicarbonate ion standard deviationinorganicAlkalinity total standard deviationAlkalinityCoulometric titrationExperimentCarbon inorganic dissolvedTemperature waterSizeCoelomic fluidCalculated using seacarb after Nisumaa et al 2010CalculatedAragonite saturation stateCtenocidaris giganteaAlkalinity totaltotalAmphipneustes loriolipHTemperaturedissolvedAcid base regulationCarbonate ionPartial pressure of carbon dioxide (water) at sea surface temperature (wet air)Carbon dioxide standard deviationSterechinus neumayeriEarth System ResearchAporocidaris eltanianaδ13Cstandard deviationField observationPolarStation labelEchinodermataPotentiometric titrationCalcite saturation stateCoelomic fluid alkalinityPotentiometricwaterPartial pressure of carbon dioxideAmphipneustes similisAragonite saturation state standard deviationBenthosDATE TIMEOcean Acidification International Coordination Centre OA ICCSterechinus antarcticusAnimaliaCalcite saturation state standard deviationBicarbonate ionLONGITUDECalculated using seacarb after Nisumaa et al. (2010)SpeciesCalculated using CO2SYScarbonEvent labelPartial pressure of carbon dioxide standard deviationCoelomic fluid carbon inorganic dissolvedCarbonate system computation flagAcid-base regulationpH standard deviationCarbonate ion standard deviationFugacity of carbon dioxide (water) at sea surface temperature (wet air)Amphipneustes rostratusPartial pressure of carbon dioxide water at sea surface temperature wet airDATE/TIMECarbon dioxideDifferenceSingle speciesCoelomic fluid pHLATITUDEFugacity of carbon dioxide water at sea surface temperature wet airAntarcticBenthic animalsCoast and continental shelfAbatus cavernosusdescription
Increasing atmospheric carbon dioxide concentration alters the chemistry of the oceans towards more acidic conditions. Polar oceans are particularly affected due to their low temperature, low carbonate content and mixing patterns, for instance upwellings. Calcifying organisms are expected to be highly impacted by the decrease in the oceans' pH and carbonate ions concentration. In particular, sea urchins, members of the phylum Echinodermata, are hypothesized to be at risk due to their high-magnesium calcite skeleton. However, tolerance to ocean acidification in metazoans is first linked to acid-base regulation capacities of the extracellular fluids. No information on this is available to date for Antarctic echinoderms and inference from temperate and tropical studies needs support. In this study, we investigated the acid-base status of 9 species of sea urchins (3 cidaroids, 2 regular euechinoids and 4 irregular echinoids). It appears that Antarctic regular euechinoids seem equipped with similar acid-base regulation systems as tropical and temperate regular euechinoids but could rely on more passive ion transfer systems, minimizing energy requirements. Cidaroids have an acid-base status similar to that of tropical cidaroids. Therefore Antarctic cidaroids will most probably not be affected by decreasing seawater pH, the pH drop linked to ocean acidification being negligible in comparison of the naturally low pH of the coelomic fluid. Irregular echinoids might not suffer from reduced seawater pH if acidosis of the coelomic fluid pH does not occur but more data on their acid-base regulation are needed. Combining these results with the resilience of Antarctic sea urchin larvae strongly suggests that these organisms might not be the expected victims of ocean acidification. However, data on the impact of other global stressors such as temperature and of the combination of the different stressors needs to be acquired to assess the sensitivity of these organisms to global change.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2015-01-01 |