Oceanography

The sea is the most obvious feature of the earth's surface. Approximately seventy percent of this surface is covered by water, in one way or another. Beneath this water are the familiar sands of the beaches, bottoms of bays, and the inshore ocean. Farther offshore this water covers an amazing submarine topography of underwater canyons, trenches, mountains, and plains. Unlike the continents, which are physically separated from one another, the oceans are continuous and interconnected. …

…coast of South America from those of Southern Africa. Regardless of this, the various regions of the world's oceans are all affected by human activity, with pollution and harvesting of resouces of resouces being common to all seas and oceans. The various marine resources, as well as the extent of human impacts on them, are examined region by region, illustrating hos stresses on the marine environmet treatened the very resistance of some habitats and species.