[Viewpoint] Deep respect for the oceans our lives depend on

The deepest part of the ocean became a movie star in March when filmmaker James Cameron corkscrewed his way to the Challenger Deep, becoming only the third person in history to visit the Mariana Trench.

One of the first people to greet Cameron when he surfaced was Don Walsh, one of the others in the elite club. Immediately after Walsh’s 1960 descent to the Mariana Trench in the bathyscaphe Trieste, he and his dive partner, the late Jacques Piccard, assumed that they would be the first of many to regularly visit the deep.

Instead the site that is just a few hundred miles from Guam went dark again for half a century.

We can’t let that happen again.

Unlike in 1960, we now have a vast capability to explore the oceans robotically. Far less sexy than Cameron’s dive were companion dives by an unmanned deep ocean vehicle (DOV) to the Mariana Trench that took place within a few days of his.

The cost of the DOV, developed largely by my colleagues at Scripps Institution of Oceanography, University of California, San Diego, is about 75 times less than what Cameron spent on his sub. No lives were in danger during the DOV’s dive.

That kind of robotic craft must be put to use as we realize how important the oceans are to life on land. We have made our seas the repository of the carbon dioxide we generate in our daily activities, the extra heat those same activities have pumped into the earth system, and a plethora of garbage that lingers just at the surface.

In return, we are extracting an unsustainable number of food fish from the oceans. We have taken oil and gases from underneath the seafloor in ways that nearly guarantee that there will be spills, leaks and other mishaps at some step of the extraction process. It’s been a bad bargain for the oceans, but it is we who will pay the price.

Deep-sea exploration could be the beginning of a reversal. It is now affordable to send fleets of DOVs to the bottom for years at a time, gathering information about life, extractable resources and ocean dynamics. Even last month’s brief trip expanded our knowledge.

Closer to the surface, another fleet of robots called Argo brought us more disturbing news in April. More than 3,500 of the floats are evenly distributed throughout the world oceans, gathering constant data on ocean temperature and salinity. Scientists analyzing that data just reported that the world’s hydrological cycle is accelerating because of the increasing heat of ocean water.

One consequence of that is that areas on land prone to drought will probably get even drier and rainy areas will get their precipitation in violent downfalls. We need to know what happens when that excess heat works its way down. Now that we can do that affordably, there’s no acceptable reason not to.

To put things in perspective, since the 1960 voyage of Trieste, there have been well more than a dozen attempts to reach Mars. Many, of course, have been successful. There are two landers on its surface and two craft orbiting the planet right now. The reality is, however, that we have a more immediate need to have that kind of presence on our own planet in places with direct impact on us. It’s really not too strong to say our lives could depend on it.

It was an act of largesse on the part of a famous and determined man to spend years developing a sub and then risk his life piloting it to shine light on earth’s darkest place.

James Cameron has a genuine love of the oceans and the science world owes him one for returning the public’s sense of wonder to the seas. Two other groups of scientists and adventurers, one including Richard Branson, have announced their own quest to reach the trench this year.

If the rest of us can exhibit at least some of that force of will, we can preserve an undersea world that is both very far away and very close. Unlike Mars, it will return the favor and keep life on the surface comfortable.

* The author is a professor and director of the Scripps Institution of Oceanography and vice chancellor of Marine Science at the University of California, San Diego, and former chief of marine and atmospheric research at Australia’s CSIRO. He will make a speech at the 6th World Ocean Forum to be held in Busan from July 4 to 6.

by Tony Haymet