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There is evidence of lower salinity in the North Atlantic coming from melting of polar ice caps and diluting the ocean with more fresh water. An increased amount of fresh water could come from glaciers or sea ice melting, an increased amount of precipitation or from rivers. The freshening of the oceans could have a damaging effect on the Ocean Conveyor. There are different scenarios for the slowing down of the ocean conveyor between the next two decade or in a hundred years (Gagosian, 2007). There is paleoclimatic evidence for rapid climatic changes as a result of the shut down of the ocean conveyor. If this were to happen, the Gulf Stream could possibly be deflected downwards, which would prevent the transfer of warm water from the tropics to the high Northern latitudes. In this scenario the high latitude would go through a very rapid cooling periods that could have devastating effects on the ecosystem (Gagosian, 2007). For this reason we assert that this region should be carefully monitored in order to recognize this trend early. There should also be a significant effort put into maintaining the robustness of the ecosystem in this area. To do this, restrictions placed on the fishery in this region should be higher than they would otherwise be set. If research proves this scenario is not the case, or that it will happen on longer time scales, such restrictions would be able to be scaled back.
Changes in Salinity in the North Atlantic (B. Dickson, et. al., in Nature, April 2002)
Australia
Studies have shown that coastal waters will warm by up to two degrees by 2030, encouraging fish to move south, threatening marine turtles, and potentially pushing box jellyfish down the east coast. Of all coasts of Australia, eastern-central and southeast domains were the most vulnerable to the impact of climate change. The movement of box jellyfish is particularly alarming because some species of these jellyfish are potentially fatal to humans. Most fishermen are only licensed to catch prawns and shrimp, as amateur fishing bans are already in place (Hannon, 2007).
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