The attached report looks at the possible effects of climate change on upwelling systems, particularly the Bonney Upwelling System which activates off the coast between Portland, Victoria and Robe, South Australia.
Upwelling systems occur off many coasts around the world and are caused by winds moving across the ocean surface which in turn draws up cold, nutrient rich water to the sea surface. The result is the attraction of ocean life to the area to feed.
The effect of climate change on these systems are difficult to predict. Some scientists argue that warmer temperatures and greater temperature differences between the air over land and sea may increase onshore wind-speed and increase upwelling. However, others argue the increased wind speed could result in increased turbidity of the water and nutrients not being present at the sea surface as long, or that increased water temperature could lead to greater stratification of the different water levels and therefore less nutrient rich water reaching the surface.
This report explores both arguments and the reasons underpinning them.