Global Climate Change In South Africa

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The phenomenon of global climate change is widely considered fact. Studies have shown that the world’s average surface temperature has been accelerated by human activities which has led to the increase in production of greenhouse gases into the atmosphere, chiefly carbon dioxide, methane and CFCs. The repercussions of this phenomenon are the increase of global sea levels, the thinning of the ozone layer, changes of annual precipitation, and an overall increase in variability and intensity of seasons, climate and weather patterns. The southern African region is undergoing the same climate changes. These changes will have an effect on the marine ecosystem and its marine fish stocks, however, only probable scenarios and predictions have been presented…show more content…
If the known changes in atmospheric and marine parameters such as temperature, Carbon dioxide concentrations, annual precipitation, atmospheric pressure and sea level pieced apart, it would show how many possible implications there are to the affected fish stocks of southern Africa. One of the parameters that will affect marine ecosystems is temperature. The global surface temperatures are increasing at a rate of about 0.15°C per decade and the observed changes in southern Africa seem to follow the global trend. The sea surface temperature off the southern African coasts has increased by 1°C since the 1940s. This water temperature increase has taken place in the deep ocean as well where in the span of thirty years, it has increased by 0.17°C. Water temperature increases have devastating effects on the marine ecosystems such coral reefs, where the microorganisms responsible for the production of coral are under…show more content…
Its influence reaches into southern Angola. In summer, winds tend to blow parallel to the coast and push surface water offshore. This allows for an upwelling of cold, nutrient-rich water to replace the surface water. Due to increased light exposure, phytoplankton blooms and becomes a food source for zooplankton and small pelagic fish. These fish species, coupled with some demersal species, forms the basis of the South African commercial fisheries industry. Uneaten phytoplankton settles on the sea bed where decomposition and oxygen consumption takes place. The lack of oxygen in the benthic areas sparks the production of hydrogen sulphide gas which can devastate marine species populations in the affected area. Times when longshore winds cease and there is little upwelling of water, blooms of red tide can occur. Red tide results in increased toxins and decreased oxygen concentration in the water which results in a large portion of marine organism populations dying. Every decade there is a movement of warm, saline, nutrient poor water that enters the Benguela upwelling system, where the upwelling is relaxed. Tropical fish species move with the warm volume of water and can be found off the coast of Namibia. This results in lower oxygen concentrations in the water as well as the displacement of many Namibian fish species. This occurrence destabilises the Namibian marine ecosystem and can result is a loss of fish

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