Sleep With The Fishes

The number of "dead zones" around the worlds oceans have increased dramatically to around 400 currently.

It's pretty scary stuff, but basically a "dead zone" is a part of the ocean where nothing (including fish, crabs and just about every other marine animal) can survive because of massive oxygen deprivation. The phenomena is known as hypoxia and is a downstream effect of chemical fertilizers used in agriculture. Air pollution, including smog from automobiles, is another factor. The nitrogen from the fertilizer and the pollution feeds the growth of algae in coastal waters, particularly during summer.

The result is feast-then-famine: The algae eventually die and sink to the bottom, where the organic matter decays in a process that robs the bottom waters of oxygen. The ensuing die-off of marine life cuts down on the productivity of commercial fisheries.

Oh and there is also a giant mass of floating plastic in the middle of the Pacific ocean that's twice the size of Texas. A group of scientists are studying the problem on a Kon-tiki style voyage, you can follow their efforts here.