Exploring the Deepest Parts of the Ocean

Scientists wire the oceans with data cables, permanent observatories, and robots that can roam for years

By Clive Thompson|Monday, October 24, 2005
RELATED TAGS: ROBOTS, OCEAN
Every time Marcia McNutt, head of Monterey Bay Aquarium Research Institute, heads out on an expedition, she wonders about all the things she won’t see: “The ocean is driven by occasional events, and when you go out on a boat, you just don’t know if you’re going to see one. It’s a lot of luck.” In many ways, oceanographers like McNutt face a greater challenge than astronauts: They cannot dive during bad weather, cannot visit the deepest areas for long, and have barely explored below the Arctic ice cap. Earth’s oceans cover an area nearly 10 times as large as the surface of the moon. “We need a new paradigm,” she says.

She is about to get one. Marine scientists are launching a slate of international projects that will wire the oceans, placing sensors and robots permanently at deep spots that can report back 24 -7. They plan to bring, in essence, a whole new planet into view.

Starting next year a global project called Neptune, for North East Pacific Time-series Undersea Networked Experiments, will lay wire-and-fiber-optic cable over a 200,000-square-mile region of the seismically active Juan de Fuca tectonic plate off the northwest coast of the United States. The cables will deliver tens of kilowatts of power so that scientists can plug sensors into the network, sending back real-time data on composition, bacteria, and more. Self-guided robotic devices will eventually be deployed to observe sudden events, such as volcanic eruptions, and then head to underwater bases for recharging. Unlike manned ocean voyages, which are inherently limited to a small crew of scientists, the network will be wired to the Internet, so researchers anywhere in the world can log on. McNutt’s group is building a test site for the American contribution to Neptune.

“It’ll be like the Hubble Space Telescope. It’s going to revolutionize marine science,” says John Delaney, head of the project and an oceanographer at the University of Washington.

Other researchers are working on complementary, mobile observatories. By next year, the Argo project will have installed 3,000 floating sensors across all the oceans, offering a daily snapshot of global patterns of water temperature and salinity—crucial for predicting the nature and pace of climate change. Within two years, scientists from the Woods Hole Oceanographic Institution and the University of Maryland will release self-guided robots to visit the hydrothermal vents deep beneath the Arctic ice shelves for the first time. The robots will collect samples of organisms that may have developed there in isolation from the rest of the world. “People think that hydrothermal vents are possibly where life began. Who knows what we’ll find?” says Woods Hole marine scientist Hanumant Singh.

Still, some predictions are easy. The new networks will speed up the cataloging of the awesome biodiversity of the oceans. Information on the growth and migration of fish stocks will become more precise. And we will have a much better grip on how the chemical cycles of aquatic life interact with temperature change—how much carbon the oceans absorb and what happens to ocean currents due to warming waters.

“We’ve already put such massive amounts of CO2 into the ocean that there’s a huge front slowly sinking to the lower depths,” McNutt says. “Organisms in the lower areas haven’t seen levels like that in 400 million years. We need to see how they adapt, and if they can.”


Shirley Pomponi, a marine biologist and the head of Harbor Branch Oceanographic Institution, is finding evidence that deep-sea organisms may provide a rich, largely untapped source of new medicines.

Why do you focus your ocean-drug studies on sea sponges?
P:
Sponges are attached to the bottom, and they can’t get away from anything that wants to eat them or grow over them. So they’ve evolved a very complex chemical warfare system. If you’re a sponge, and another sponge wants to occupy the space you’re in, you produce a chemical that’s going to kill those cells. This might be something useful for preventing another cell from rapidly dividing—such as a cancer cell. Sponges might also secrete something that helps them be more immune to the attack; that chemical could be useful in controlling inflammation. Or they secrete compounds to prevent larvae from settling on them; those chemicals may be similar to molecules that are involved in controlling blood pressure.

Have there been any worthwhile discoveries?
P:
We found discodermolide [a drug from Discodermia, a sponge found in the Caribbean, the Bahamas, and the Gulf of Mexico], and it’s gone through phase I clinical trials for treatment of solid tumors such as ovarian, pancreatic, breast, colon, or lung cancers. Another success story is Prialt, discovered by a University of Utah team studying a fish-eating cone snail. The snail sends out a barb, snags a fish, paralyzes it with a suite of toxins, and eats it. One of the toxins has been used to create a drug for pain management in AIDS and cancer patients.

What parts of the ocean do we need to explore most urgently?
P:
Historically, in the search for drugs from the sea, we’ve looked primarily at animals that are attached to the bottom. But there are also all these worms and other animals that live in the mud, in the vast abyssal plains of the ocean, in methane ice. Boy, I bet they’re producing some interesting stuff! And there are all the animals that live in the midwater environment. Jellyfish probably make up the second-largest biomass on Earth, and we haven’t even looked at them. There’s also an enormous number of bacteria that have never been investigated.

Should we send humans into the oceans, or are robotic probes better?
P:
There’s nothing better than being there. When we were in the methane ice in the Gulf of Mexico, we used one of our submersibles that has 360-degree visibility because you’re sitting in a plastic bubble. And the pilot just happened to kind of look out of the corner of his eye and say, “Hey, what’s that moving on that methane ice?” That’s how we discovered ice worms.

Is it more important to spend money exploring space or the oceans?
P:
I love space exploration, but I think that many people would be amazed to learn that only two human beings have ever gone to the deepest part of the ocean—the Mariana Trench—and that was more than 30 years ago. It’s only seven miles deep. We’re talking about sending people millions of miles away, but we’ve yet to explore our own planet. People have been diving around the Florida Keys for over a century, yet we can still go five miles offshore and find an entirely new species of sponge that has anticancer properties. There is some very cool stuff in our own backyard.


What's going down in the oceans

In the next few years, a new generation of submersibles will begin to transform marine science by opening up enormous unexplored regions of the ocean. Here are the most notable ones.

Argo
Function: An adjustable oil pack allows the buoy to sink and rise every 10 days, radioing data to satellites when it surfaces. Collects data on salinity, temperature, and pressure—fundamental data on all types of environmental change, from varying weather conditions to climate variations.
Maximum depth: 6,500 feet
When: 1,870 in use; 3,000 next year

Spray
Function: As with Argo, an adjustable oil pack enables this underwater glider to sink and rise, while wings on each side propel it forward at 10 inches per second. Sensors measure data including nutrient density, chlorophyll abundance, and current motions to map ocean dynamics; a GPS tracker reports its location.
Maximum depth: 5,000 feet
When: Four in use; missions began in 2003

Puma and Jaguar
Function: Onboard computer systems navigate these vehicles autonomously through the mysterious, ice-riddled waters beneath the Arctic shelf. Puma navigates and hunts for hydrothermal vents using chemical sniffers and lasers to detect smoke traces. When Puma locates a vent, Jaguar dives down, takes pictures, makes sonar maps, and gathers biological samples using a manipulator arm.
Maximum depth: 6,500 feet
When: 2007; one pair to be built

Alvin replacement
Function: A manned submersible with five windows—two more than the current workhorse, called Alvin—this craft dives 6,500 feet deeper, putting 99 percent of the ocean within its range. Manipulator arms bring in specimens, sonar scans the ocean floor, cameras image surroundings, and a fiber-optic antenna lets ship scientists participate in expeditions remotely.
Maximum depth: 21,000 feet
When: 2009

Hybrid remotely operated vehicle
Function: Ceramic pressure housing gives access to the deepest trenches in the ocean. In autonomous mode, it can collect 36 hours’ worth of sonar images, temperature and chemical readings, and pictures and video, guided entirely by onboard computers. In remotely operated mode, HROV can be controlled via a fiber-optic tether just one-thirty second of an inch thick. A manipulator arm and retrieval baskets can collect physical specimens.
Maximum depth: 35,000 feet
When: Next year

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