Photosynthetic organisms in the sea yield most of the oxygen in the atmosphere, take up and store vast amounts of carbon dioxide, shape planetary chemistry, and hold the planet steady.

It is not too late to turn things around.

We have an atmosphere that is roughly 21% oxygen. The rest of it is largely nitrogen. There's just enough carbon dioxide (CO2) to drive photosynthesis. That has been, throughout the history of our species, pretty stable. Until recently.

Forty percent of the United States drains into the Mississippi. It's agriculture. It's golf courses. It's domestic runoff from our lawns and roads. Ultimately, where does it go? Downstream into the gulf.

When I first ventured into the Gulf of Mexico in the 1950s, the sea appeared to be a blue infinity too large, too wild to be harmed by anything that people could do.

Our job is to keep what is working intact and not destroy what we have got.

The living ocean drives planetary chemistry, governs climate and weather, and otherwise provides the cornerstone of the life-support system for all creatures on our planet, from deep-sea starfish to desert sagebrush. That's why the ocean matters. If the sea is sick, we'll feel it. If it dies, we die. Our future and the state of the oceans are one.