The impacts of past, present and future ocean chemistry on predatory planktonic snails

• Published in: Royal Society Open Science
• Main Authors: Wall-Palmer, Debbie, Mekkes, Lisette, Ramos-Silva, Paula, Dämmer, Linda K., Goetze, Erica, Bakker, Karel, Duijm, Elza, Peijnenburg, Katja T. C. A.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2021
• Subjects: atlantidae; ocean acidification; calcification; calcein indicator; gene expression; micro-CT; Ocean acidification
• Online Access: https://zenodo.org/record/6381645; https://doi.org/10.1098/rsos.202265

The atlantid heteropods represent the only predatory, aragonite shelled zooplankton. Atlantid shell production is likely to be sensitive to ocean acidification (OA), and yet we know little about their mechanisms of calcification, or their response to changing ocean chemistry. Here, we present the first study into calcification and gene expression effects of short-term OA exposure on juvenile atlantids across three pH scenarios: mid- 1960s, ambient and 2050 conditions. Calcification and gene expression indicate a distinct response to each treatment. Shell extension and shell volume were reduced from the mid-1960s to ambient conditions, suggesting that calcification is already limited in today’s South Atlantic. However, shell extension increased from ambient to 2050 conditions. Genes involved in protein synthesis were consistently upregulated, whereas genes involved in organismal development were downregulated with decreasing pH. Biomineralization genes were upregulated in the mid-1960s and 2050 conditions, suggesting that any deviation from ambient carbonate chemistry causes stress, resulting in rapid shell growth. We conclude that atlantid calcification is likely to be negatively affected by future OA. However, we also found that plentiful food increased shell extension and shell thickness, and so synergistic factors are likely to impact the resilience of atlantids in an acidifying ocean. Funding: This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 746186 [POSEIDoN, DW-P] and grant agreement no. 844345 [EPIC, PRS]. Plankton collection on the AMT27 cruise was funded by a Vidi grant no. (016.161351) from the Netherlands Organisation for Scientific Research (NWO) to KTCAP. The Atlantic Meridional Transect is funded by the UK Natural Environment Research Council through its National Capability Long-term Single Centre Science Programme, Climate Linked Atlantic Sector Science (grant no. NE/R015953/1). This ...