CO 2 -induced ocean acidification does not affect individual or group behaviour in a temperate damselfish
Open ocean surface CO 2 levels are projected to reach approximately 800 µatm, and ocean pH to decrease by approximately 0.3 units by the year 2100 due to anthropogenic CO 2 emissions and the subsequent process of ocean acidification (OA). When exposed to these CO 2 /pH values, several fish species d...
Published in: | Royal Society Open Science |
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Main Authors: | , , |
Other Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
The Royal Society
2017
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Subjects: | |
Online Access: | http://dx.doi.org/10.1098/rsos.170283 https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.170283 https://royalsocietypublishing.org/doi/full-xml/10.1098/rsos.170283 |
Summary: | Open ocean surface CO 2 levels are projected to reach approximately 800 µatm, and ocean pH to decrease by approximately 0.3 units by the year 2100 due to anthropogenic CO 2 emissions and the subsequent process of ocean acidification (OA). When exposed to these CO 2 /pH values, several fish species display abnormal behaviour in laboratory tests, an effect proposed to be linked to altered neuronal GABA A receptor function. Juvenile blacksmith ( Chromis punctipinnis ) are social fish that regularly experience CO 2 /pH fluctuations through kelp forest diurnal primary production and upwelling events, so we hypothesized that they might be resilient to OA. Blacksmiths were exposed to control conditions (pH ∼ 7.92; p CO 2 ∼ 540 µatm), constant acidification (pH ∼ 7.71; p CO 2 ∼ 921 µatm) and oscillating acidification (pH ∼ 7.91, p CO 2 ∼ 560 µatm (day), pH ∼ 7.70, p CO 2 ∼ 955 µatm (night)), and caught and tested in two seasons of the year when the ocean temperature was different: winter (16.5 ± 0.1°C) and summer (23.1 ± 0.1°C). Neither constant nor oscillating CO 2 -induced acidification affected blacksmith individual light/dark preference, inter-individual distance in a shoal or the shoal's response to a novel object, suggesting that blacksmiths are tolerant to projected future OA conditions. However, blacksmiths tested during the winter demonstrated significantly higher dark preference in the individual light/dark preference test, thus confirming season and/or water temperature as relevant factors to consider in behavioural tests. |
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