Publication Date:
2024-03-19
Description:
Shelled pteropods are widely regarded as bioindicators for ocean acidification, because their fragile aragonite shells are susceptible to increasing ocean acidity. While short-term incubations have demonstrated that pteropod calcification is negatively impacted by ocean acidification, we know little about net calcification in response to varying ocean conditions in natural populations. Here, we examine in situ calcification of Limacina helicina pteropods collected from the California Current Ecosystem, a coastal upwelling system with strong spatial gradients in ocean carbonate chemistry, dissolved oxygen and temperature. Depth-averaged pH ranged from 8.03 in warmer offshore waters to 7.77 in cold CO2-rich waters nearshore. Based on high-resolution micro-CT technology, we showed that shell thickness declined by 37% along the upwelling gradient from offshore to nearshore water. Dissolution marks covered only 2% of the shell surface area and were not associated with the observed variation in shell thickness. We thus infer that pteropods make thinner shells where upwelling brings more acidified and colder waters to the surface. Probably the thinner shells do not result from enhanced dissolution, but are due to a decline in calcification. Reduced calcification of pteropods is likely to have major ecological and biogeochemical implications for the cycling of calcium carbonate in the oceans.
Keywords:
Alkalinity, total; Animalia; Aragonite saturation state; Bicarbonate ion; Calcification/Dissolution; Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Coast and continental shelf; Diameter; Dissolution; Field observation; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Growth/Morphology; Height; Identification; LATITUDE; Limacina helicina; Location; LONGITUDE; Mollusca; North Pacific; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Pelagos; pH; Phosphate; Registration number of species; Salinity; Shell, number of whorls; Shell surface area; Shell thickness; Silicate; Single species; Species; Station label; Temperate; Temperature, water; Type; Uniform resource locator/link to reference; Upwelling; Zooplankton
Type:
Dataset
Format:
text/tab-separated-values, 2250 data points
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