He says current knowledge of life on the ocean floor is especially limited.

VOA: special.2009.01.13

And,it explains how life on land depends on life in the ocean.

VOA: special.2009.04.03

"He was telling us, not only our family, but more and more the public, 'Don't use the ocean as a garbage can, as a universal sewer because it's a life support system.

VOA: standard.2010.06.18