I've run across an excellent website for gaining a "big-picture" understanding of the current state of the world's oceans.
Oceans inc is a multi-media platform dedicated to transmitting news about the ocean. It is concerned solely with what affects the ocean and the measures necessary to preserve it for humankind.
Ocean inc covers key ocean events around the world, issuing TV and written news as well as live coverage via social media. Follow Ocean inc for major ocean events throughout the year and on Twitter via @oceans_inc