The waters of the Great Australian Bight are highly biodiverse, particularly in zooplankton, due to a particular series of ocean currents. A literature review undertaken by SARDI (South Australian Research and Development Institute) on the Benthic Protection Zone of the Great Australian Bight Marine Park in 2003 states: "Upwelling events during summer and autumn produce cool patches of surface water along the coast of the southern Eyre Peninsula. These patches contain elevated nutrient concentrations and support enhanced levels of primary productivity. High densities of zooplankton to the northwest of the patches indicate that the prevailing southeasterly winds transport the products of this enhanced biological production into the central GAB. These plankton communities support the highest densities of small planktivorous fishes, including sardine and anchovy, in Australian waters. Juvenile southern bluefin tuna (SBT) migrate into the GAB annually to feed on these rich pelagic resources."