into the environment. Many human activities—industrial production, burning
of fossil fuels, agriculture, and product use, among others—generate pollutants
that can find their way into the ocean. At one time, people thought
that the vastness of the ocean could dilute pollutants enough to eliminate their
impacts. It is now known, however, that some pollutants can significantly alter
marine ecosystems and cause harm—sometimes deadly—to species from the top to
the bottom of the food web.