Acidification Marine pollution

island fringing reef in maldives. coral reefs dying around world.

the oceans natural carbon sink, absorbing carbon dioxide atmosphere. because levels of atmospheric carbon dioxide increasing, oceans becoming more acidic. potential consequences of ocean acidification not understood, there concerns structures made of calcium carbonate may become vulnerable dissolution, affecting corals , ability of shellfish form shells.

oceans , coastal ecosystems play important role in global carbon cycle , have removed 25% of carbon dioxide emitted human activities between 2000 , 2007 , half anthropogenic co2 released since start of industrial revolution. rising ocean temperatures , ocean acidification means capacity of ocean carbon sink gradually weaker, giving rise global concerns expressed in monaco , manado declarations.

a report noaa scientists published in journal science in may 2008 found large amounts of relatively acidified water upwelling within 4 miles of pacific continental shelf area of north america. area critical zone local marine life lives or born. while paper dealt areas vancouver northern california, other continental shelf areas may experiencing similar effects.

a related issue methane clathrate reservoirs found under sediments on ocean floors. these trap large amounts of greenhouse gas methane, ocean warming has potential release. in 2004 global inventory of ocean methane clathrates estimated occupy between 1 , 5 million cubic kilometres. if these clathrates spread uniformly across ocean floor, translate thickness between 3 , fourteen metres. estimate corresponds 500–2500 gigatonnes carbon (gt c), , can compared 5000 gt c estimated other fossil fuel reserves.