11 Oceans

"Imagine that an alien were visiting Earth for the first time to explore its landscape and inhabitants. It would have a 72% chance to “land” the spaceship on the ocean, because this is how much of our planet is ocean. But if the alien asked us about this largest feature of our planet, there would be huge gaps in our description. We have more detailed maps of the surface of the moon than of the bottom of the ocean, and we have explored in detail less than 5% of the ocean. Unfortunately, the technology that allows humans to descend into the deep only became available long after we had begun to degrade the ocean. Our understanding of ocean life is a by-product of studying degraded ecosystems, like trying to understand how a car functions by studying a car wreck in a junkyard.

Despite these shortcomings, we have learned enough about the ocean to know that it regulates our climate, is vital for the water cycle that creates the rain that waters our forests and fields, produces more than half of the oxygen we breathe, absorbs more than a quarter of the carbon dioxide we put in the atmosphere, gives us almost 100 million metric tonnes of seafood every year, and provides jobs and livelihoods for hundreds of millions of people worldwide. Despite everything the ocean gives us for free, we seem determined to degrade marine life, by taking out of the ocean what we like (seafood) and throwing in what we don’t want (pollution, carbon dioxide, excess heat). These insults reduce the capacity of the ocean to provide all these goods and services that are essential to our well-being.

To find solutions to these problems, we need to start by reviewing what we know about the ocean..."