Robustness of Adamussium colbecki shell to ocean acidification in a short-term exposure

Abstract

Atmospheric pCO2 has increased since the industrial revolution leading to a lowering of the ocean surface water pH, a phenomenon called ocean acidification (OA). OA is claimed to be a major threat for marine organisms and ecosystems and, particularly, for Polar regions. We 2 explored the impact of OA on the shell mechanical properties of the Antarctic scallop Adamussium colbecki exposed for one month to acidified (pH 7.6) and natural conditions (unmanipulated littoral water), by performing Scanning Electron Microscopy, nanoindentation and Vickers indentation on the scallop shell. No effect of pH could be detected either in crystal deposition or in the mechanical properties. A. colbecki shell was found to be resistant to OA, which suggests this species to be able to face a climate change scenario that may threat the persistence of the endemic Antarctic species. Further investigation should be carried out in order to elucidate the destiny of this key species in light of global change.

Growth of marine ectotherms is regionally constrained and asymmetric with latitude

“…The only exception to this pattern is the Antarctic scallop, Adamussium colbecki , which remains within expectation and uplifts mean OGP in the Southern Ocean while increasing variability. Higher OGP in A. colbecki most likely reflects a species‐specific adaptation in shell morphology that has been driven by evolutionary history at cold temperatures (Berkman et al, 2004; Watson et al, 2017; Dell’Acqua et al, 2019). This revelation is striking, because A. colbecki is routinely used as a model species for physiological studies in the Antarctic (Moro et al., 2019), meaning that a priori assessments of the physiological responses of polar ecosystems to climate warming may underestimate species vulnerability in the Antarctic whilst overestimating species vulnerability in the Arctic.…”

The impact of environmental acidification on the microstructure and mechanical integrity of marine invertebrate skeletons

“…Reduced shell growth and thinning of shells under experimental CO 2 acidification have been observed using SEM at both the larval (Gazeau et al ., 2010; Parker et al ., 2012; Fitzer et al ., 2014a) and adult stages (Gazeau et al ., 2013; Fitzer et al ., 2014b). However, no effect on shape or size of crystals was observed in the clam Arctica islandica or the scallop Adamussium colbecki under elevated CO 2 (Stemmer et al ., 2013, Dell’ Acqua et al ., 2019). The abnormalities and changes to shell growth can affect bivalves at the microstructure level of the forming phases of aragonite and calcite (Wehrmeister et al ., 2011), and can also impact the amorphous calcium carbonate (ACC) that is an important precursor of crystalline carbonate minerals (Addadi et al .…”

Effect of low pH on growth and shell mechanical properties of the Peruvian scallop Argopecten purpuratus (Lamarck, 1819)

“…In addition, experimental low pH studies have highlighted a CaCO3 chaotic crystal deposition that weakens the skeleton as Cnidaria, Annelida, Bivalvia, and Cephalopoda (Byrne and Fitzer, 2019). Nevertheless, under ocean acidification, mechanical characterization has only been applied to 9 species from 6 families of bivalve (Byrne and Fitzer, 2019), and for Pectinidae, just one specie was studied (Dell'Acqua et al, 2019). Mineral structure and mechanical integrity characterization are needed for a complete understanding of the impact of low pH on calcifying organisms (Byrne and Fitzer, 2019).…”