In Challenge of the Seas, Vol. 10: In Over Our Heads, students are presented with information regarding the threats to ocean environments, and efforts to overcome these severe problems. For millennia, people have looked to the oceans for food, and have harvested its abundant waters. As world populations have risen, there has been a corresponding demand for more seafood, and commercial fishermen have overfished many areas of the oceans. Oceans are also thought of as huge dumping grounds for all manner of wastes, including toxic chemicals and heavy metals. ~ Alice Day, All Movie Guide