How can such a wide–spread effect, like acidification associated with global climate change, be adequately addressed? Approximately half of the carbon dioxide (CO2) produced by human activity in the last 200 years has been taken up by the oceans. CO2 in the atmosphere is a chemically unreactive gas, but when it is dissolved in the ocean chemical changes occur. One of the overall effects is the formation of carbonic acid (H2O + CO2 = H2CO). This weak acid releases hydrogen ions into the seawater, which causes the acidity to increase (lowering the pH). The increase in ocean acidity has consequences for marine organisms that produce calcium carbonate (CaCO3). Marine life such as corals, molluscs, phytoplankton and zooplankton could be severely impacted, causing a ripple effect through the entire marine food chain. The ink print in the painting is directly from a Fraser River Sockeye (Oncorhynchus nerka), and the green background at the bottom represents the upwelling of cooler water that the salmon prefer. The ochre water is surface water that has been de-oxygenated by a plankton bloom and the circular object is a centric diatom.
|
