Mechanisms of mollusc biomineralisation under climate change: what we know and what we need to find out

Mechanisms of mollusc biomineralisation under climate change: what we know and what we need to find out

Issued: Tue, 12 Dec 2017 14:00:00 GMT

SUERC Seminar Series

12 December

Mechanisms of mollusc biomineralisation under climate change: what we know and what we need to find out

Susan Fitzer, GES, University of Glasgow

Global climate change threatens the oceans as anthropogenic carbon dioxide causes ocean acidification and warming. The amount of carbonate available in the oceans under ocean acidification will be reduced. Calcifying organisms, such as shellfish, are those at most risk from such ocean acidification, as carbonate is vital in the biomineralisation of their calcium carbonate protective shells.

There is uncertainty behind the mechanisms of carbonate uptake, carbonate can be sourced through the environment as dissolved inorganic carbon as carbonate or hydrogen carbonate. Molluscs can also incorporate metabolically derived carbon through CO2 entering the extrapallial fluid by diffusion from the mantle tissue.

The ability to differentiate between these carbonate sources is a crucial gap in knowledge for defining the pathways involved in biomineral shell production. The mineral specific carbon source and route for mollusc shell production or ‘biomineralisation pathway’ has been examined under ocean acidification and warming.

Here I present data for the mussel, M. edulis, which suggests that ocean acidification can implement a fundamental shift in the carbon source utilised for biomineralisation. This research highlights the reduced capacity of mussels to biomineralise, sourcing carbon in the form of carbonate rather than tissue bicarbonate produced via protein activity.

Projections for ocean acidification and reduced carbonate saturation levels may prove detrimental to mussel shell production. Knowledge of the mineral specific biomineralisation pathways, in combination with the shell physical properties, will enable accurate predictions of the vulnerability of these mollusc species to future climate change.

Global climate change threatens the oceans as anthropogenic carbon dioxide causes ocean acidification and warming. The amount of carbonate available in the oceans under ocean acidification will be reduced. Calcifying organisms, such as shellfish, are those at most risk from such ocean acidification, as carbonate is vital in the biomineralisation of their calcium carbonate protective shells. There is uncertainty behind the mechanisms of carbonate uptake, carbonate can be sourced through the environment as dissolved inorganic carbon as carbonate or hydrogen carbonate. Molluscs can also incorporate metabolically derived carbon through CO2 entering the extrapallial fluid by diffusion from the mantle tissue. The ability to differentiate between these carbonate sources is a crucial gap in knowledge for defining the pathways involved in biomineral shell production. The mineral specific carbon source and route for mollusc shell production or ‘biomineralisation pathway’ has been examined under ocean acidification and warming. Here I present data for the mussel, M. edulis, which suggests that ocean acidification can implement a fundamental shift in the carbon source utilised for biomineralisation. This research highlights the reduced capacity of mussels to biomineralise, sourcing carbon in the form of carbonate rather than tissue bicarbonate produced via protein activity. Projections for ocean acidification and reduced carbonate saturation levels may prove detrimental to mussel shell production. Knowledge of the mineral specific biomineralisation pathways, in combination with the shell physical properties, will enable accurate predictions of the vulnerability of these mollusc species to future climate change.