| Summary: | The human activities of deforestation, burning of fossil fuels and cement production have contributed to increasing anthropogenic carbon emissions in the atmosphere. The resulting effect is a greenhouse effect, leading to warming of our oceans. The high amounts of carbon dioxide, can also enter through ocean surfaces and form chemical reactions with seawater, leading to ocean acidification. Warming of our oceans and lowering of oceanic pH are environmental stresses that can induce disturbances in physiological and biological processes, thereby impacting the wellbeing of marine organisms. This study aims to examine the effects of climate change namely ocean warming and acidification on the responses of the green mussel Perna viridis using biomarkers at the cellular, physiological and biochemical level. The biomarkers examined are the: Neutral Red Retention Time (NRRT), Ferric Reducing Antioxidant Power (FRAP), Glycogen levels, Total Glutathione (GSH-t) and Heat Shock Protein 70 (HSP70). P. viridis were subjected to acidification stress at pH 7.4 and pH 7.7 and also subjected separately to thermal treatment at 26°C, 30° C, 32° C and 34° C. The results indicated decreased NRRT for acidification stress and during extreme thermal treatment of 32° C and 34° C. For antioxidant biomarkers, both acidification and thermal stress gave rise to lower FRAP responses, while for the GSH-t assay, only the pH of 7.4 and the cooler temperature of 26° C gave rise to lower GSH-t levels. As a general biomarker, glycogen levels showed no significant differences between acidification treatments. However, glycogen levels were significantly different between exposure duration and they were observed to decrease with increasing duration of exposure. Thermal treatments at 26°C and 30°C were also observed to decrease glycogen levels at chronic exposure duration of five days. Thermal treatment of 32°C and 34°C also resulted in low glycogen levels at Day 1. For the HSP70 response, higher levels of induced HSP70 levels were seen during ...
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