University Of Tasmania

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Before ocean acidification: calcifier chemistry lessons

journal contribution
posted on 2023-05-18, 00:49 authored by Roleda, M, Philip BoydPhilip Boyd, Catriona HurdCatriona Hurd
Ocean Acidification (OA) has been an important research topic for a decade. Scientists have focused on how the predicted 56% decline in the seawater carbonate ion (CO2-3> ) concentration will dramatically impair the ability of calcifiers, ranging from coccolithophores to shellfish, to form calcium carbonate (CaCO3) structures, and the implications of the reduced carbonate saturation state (X) for increased dissolution of such structures. However, many published OA studies have overlooked a fundamental issue: most calcifying organisms do not rely on carbonate from seawater to calcify; they use either bicarbonate (HCO3- ) or metabolically-produced CO2. The ability of important primary (corals, coralline seaweeds, and coccolithophores) and secondary (mollusks) producers to modify their local carbonate chemistry suggests that the primary threat to them from OA is by dissolution rather than impaired calcification. Here, we draw on calcification research from an era before OA and combine it with recent studies that question the source of the carbonate ion, to provide new insights into how OA might affect calcifying organisms. Organismal modification of local carbonate chemistry may enable some calcifiers to successfully form calcareous structures despite OA. Key index words: calcification; carbonate chemistry; carbonic anhydrase; coccolithophores; coralline macroalgae; corals; invertebrate; molluscs; ocean acidification; physiological chemistry Abbreviations: X, carbonate saturation state; CA, carbonic anhydrase; CaCO3, calcium carbonate; CO2-3> , carbonate; CO2, carbon dioxide; DIC, dissolved inorganic carbon; H+, hydrogen ion; HCO3 ), bicarbonate; OA, ocean acidification


Publication title

Journal of Phycology








Institute for Marine and Antarctic Studies


Blackwell Publishing Inc

Place of publication

350 Main St, Malden, USA, Ma, 02148

Rights statement

Copyright 2012 Phycological Society of America

Repository Status

  • Restricted

Socio-economic Objectives

Ecosystem adaptation to climate change

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