MADRID — The International Union for Conservation of Nature (IUCN), warns that climate change and nutrient pollution are depleting the oceans of oxygen in a report published in December. <br /><br />The report states that nitrogen and phosphorus runoffs from sewage, agricultural waste and industrial pollution are the main cause of oxygen deletion, especially in coastal seas.<br /><br />According to the BBC, the study also found that climate change is heating the oceans and reducing the amount of oxygen they can hold. <br /><br />The study found the oxygen dissolved in the ocean has dropped two percent globally and as much as 40 percent in parts of the tropics.<br /><br />The study warns that the combined effects of warmer oceans and run offs could affect the top 1,000 meter of the water column, which is richest in biodiversity.<br /><br />The IUCN states that deoxygenation harms bigger fish that are oxygen sensitive, such as tuna, marlin and sharks, but favors microbes and jellyfish that are not.<br /><br />The report suggests that the lack of oxygen would force the fish to live closer to the surface, where they are vulnerable to overfishing.
