ABSTRACT
Most scientists agree that the currently observed climate change is due to the anthropogenic emission of carbon dioxide from fossil fuel burning, tropical deforestation and increased livestock production. Ocean deoxygenation is closely related to climate change. As ocean surface heating reduces gas solubility and enhances stratification of seawater, ocean O2 content is thought to decline. The physical and chemical environment in upwelling regions with high production have also undergone dramatic changes owing to the increase of the atmospheric CO2 concentration caused by human activities and the related climate change. Ocean deoxygenation and acidification have synergistic or antagonistic effects on photosynthetic carbon fixation, respiration, photorespiration, growth and calcification and we need to pay more attention on this unpredictable issue. Increasing atmospheric carbon dioxide concentrations are reflected by a rising CO2 partial pressure in surface waters resulting in increasing H+ concentrations causing ocean acidification.
