Supplementary material from "Fluctuating seawater pH/ p CO 2 regimes are more energetically expensive than static pH/ p CO 2 levels in the mussel Mytilus edulis "

Ocean acidification (OA) studies typically use stable open-ocean pH or CO 2 values. However, species living within dynamic coastal environments can naturally experience wide fluctuations in abiotic factors, suggesting their responses to stable pH conditions may not be reflective of either present or...

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Bibliographic Details
Main Authors: Mangan, Stephanie, Urbina, Mauricio A., Findlay, Helen S., Wilson, Rod W., Lewis, Ceri
Format: Article in Journal/Newspaper
Language:unknown
Published: Figshare 2017
Subjects:
Online Access:https://dx.doi.org/10.6084/m9.figshare.c.3893878
https://figshare.com/collections/Supplementary_material_from_Fluctuating_seawater_pH_i_p_i_CO_sub_2_sub_regimes_are_more_energetically_expensive_than_static_pH_i_p_i_CO_sub_2_sub_levels_in_the_mussel_i_Mytilus_edulis_i_/3893878
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Summary:Ocean acidification (OA) studies typically use stable open-ocean pH or CO 2 values. However, species living within dynamic coastal environments can naturally experience wide fluctuations in abiotic factors, suggesting their responses to stable pH conditions may not be reflective of either present or near-future conditions. Here we investigate the physiological responses of the mussel Mytilus edulis to variable seawater pH conditions over short (6 h) and medium-term (2 weeks) exposures under both current and near-future (OA) scenarios. Mussel haemolymph pH closely mirrored that of seawater pH over short-term changes of 1 pH unit with acidosis or recovery accordingly, highlighting a limited capacity for acid–base regulation. After 2 weeks, mussels under variable pH conditions had significantly higher metabolic rates, antioxidant enzyme activities and lipid peroxidation than those exposed to static pH under both current and near-future (OA) scenarios. Static near-future pH conditions induced significant acid–base disturbances and lipid peroxidation compared with the static present-day conditions but did not affect the metabolic rate. These results clearly demonstrate that living in naturally variable environments is energetically more expensive than living in static seawater conditions, which has consequences for how we extrapolate future OA responses in coastal species.