National Public Radio: ARUN RATH, HOST: A recent report on the health of the oceans includes some welcome good news. Ocean habitats seem to be in pretty good shape, at least compared to things on land. Douglas McCauley is an ecologist at UC Santa Barbara and a lead author of the study. DOUGLAS MCCAULEY: To put things into numbers, in the past 500 years, we've seen on land 500 animal extinctions occur. In the oceans - the same time period - only 15 marine animals have been driven extinct. RATH: Now, having seen the whole...