Oceans form a very important part of our environment. If three-fourth of the world is covered by oceans, you can well imagine the impact of oceans on the overall environment. This makes the health of an ocean an important factor but yet we see today that ocean pollution is the biggest in the world. There exists a whole separate world of marine ecosystem and marine creatures under the oceans. Human activities are having an adverse impact on marine life and one of the biggest examples of that is the instance of dead zones around the world.