The role of CO2 variability and exposure time for biological impacts of ocean acidification

Biological impacts of ocean acidification have mostly been studied using future levels of CO without consideration of natural variability or how this modulates both duration and magnitude of CO exposure. Here we combine results from laboratory studies on coral reef fish with diurnal in situ CO data...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Shaw, Emily C., Munday, Philip L., McNeil, Ben I.
Format: Article in Journal/Newspaper
Language:English
Published: Wiley-Blackwell 2013
Subjects:
Online Access:https://espace.library.uq.edu.au/view/UQ:313915/UQ313915OA.pdf
https://espace.library.uq.edu.au/view/UQ:313915
Description
Summary:Biological impacts of ocean acidification have mostly been studied using future levels of CO without consideration of natural variability or how this modulates both duration and magnitude of CO exposure. Here we combine results from laboratory studies on coral reef fish with diurnal in situ CO data from a shallow coral reef, to demonstrate how natural variability alters exposure times for marine organisms under increasingly high-CO conditions. Large in situ CO variability already results in exposure of coral reef fish to short-term CO levels higher than laboratory-derived critical CO levels (∼600 μatm). However, we suggest that the in situ exposure time is presently insufficient to induce negative effects observed in laboratory studies. Our results suggest that both exposure time and the magnitude of CO levels will be important in determining the response of organisms to future ocean acidification, where both will increase markedly with future increases in CO. Key Points Seawater CO2 variability alters in situ CO2 exposure time and magnitude Fish are presently exposed to short-term CO2 levels above critical values Acidification experiments should consider both CO2 level and exposure times