Despite some good news, such as Palau's National Marine Sanctuary that will roughly be the size of California (see map below) and help protect 1,300 species of fish and 700 species of coral, ocean conservation at the "baby steps" phase of its evolution. Most of the world's oceans are in a kind of blind spot; there might be treaties that try to keep bad behavior to a minimum, but nobody really knows what is going on, keeps track, or can even realistically enforce any rules. Destructive over-fishing and bottom trawling, ships that burn the dirtiest of bunker fuels ("Just 15 of the world's biggest ships may now emit as much pollution as all the world's 760m cars), toxic waste dumping, etc. One study looked at 18,000 hours of deep sea footage and basically found that the ocean seafloor is covered in trash...
In 2010, almost 200 countries met in Nagoya, Japan. They adopted the U.N. 'Aichi Targets' to try to stop the rapid loss of biodiversity. The countries committed to protecting at least 10% of the ocean by 2020.
How are we doing so far? Not that great. A recent study by the researchers at the University of British Columbia in Canada found that only 4% of the ocean is protected. And not even all the places that are protected benefit from truly bulletproof protection; many marine protected areas (MPAs) don't have "no-take" rules that are actually enforced.
“No-take” marine protected areas are zones where it is prohibited to extract any resources, including living resources, such as fish, crustaceans, and seaweed, and non-living resources, such as oil and gas. Only 16 per cent of the area that is protected or 0.5 per cent of the global ocean—is designated as “no take.” (source)
The glass-half-full way to look at this is that there's been progress: In 2006, only an estimated 0.65% of the ocean was protected... But even with today's numbers, this leaves 96% unprotected, and 99.5% without a 'no-take' ban on fishing.
“Given the creation of very large marine protected areas in recent years, notably though the Global Ocean Legacy Project of the Pew Charitable Trusts, there is a chance that the Aichi Targets can be reached, which would be a major achievement,” said co-author Daniel Pauly, a professor at the Institute for Ocean and Fisheries.