The bottom of the world's ocean contains vast supplies of precious metals and other resources, including gold, diamonds, and cobalt. Now, as the first deep-sea mining project ramps up, nations are trying to hammer out guidelines to ensure this new "gold rush" doesn't wreck the oceans.

People have dreamed of harvesting riches from the seafloor for decades. A project off Papua New Guinea could begin as early as 2018, serving as a test case for an industry that could be highly lucrative. If it proves successful, it could kick off a boom of deep-sea mining around the world.

In response, representatives of many nations, the mining industry, and environmental groups are meeting this week in Kingston, Jamaica, at an annual session of the International Seabed Authority. The purpose is to agree on safeguards and operating procedures for deep-sea mining, especially in the high seas. Under international jurisdiction, the high seas represent roughly two-thirds of the world’s oceans.

"Nations should act now to make sure our ocean is protected as this new industry develops," says Conn Nugent, who is the director of the deep-sea mining project with the Pew Charitable Trusts.

The International Seabed Authority was established in 1994 through the United Nations, based on the 1982 Convention on the Law of the Sea. The authority is charged with protecting the ocean from impacts of mining and ensuring landlocked countries can share some of the benefits. A draft of new guidelines is expected in the next few weeks, with ratification likely to take a few years.

Until then, here’s what you need to know:

What Kinds of Things Would Deep-Sea Miners Look For?

The diamond conglomerate De Beers has been mining diamonds from shallow waters off southwest Africa since the 1960s, so harvesting diamonds from deeper water is a possibility. Precious metals such as gold, silver, and copper are also attractive targets.

So are useful metals like zinc and manganese, as well as rare earth materials such as cobalt, which are used in high-tech devices from cell phones to computers. As more of the world adopts advancing technology, these materials are likely to see rising demand, and supply on land is relatively limited (hence the name "rare earth").

The valuable materials are likely to occur in higher concentrations on the seafloor than in many land-based mines, experts predict. They appear in nodules that litter the seafloor and in crusts of manganese or sulfide deposits, especially near hydrothermal vents. These minerals can be found between a few hundred feet and about 20,000 feet (6,100 meters) down.

How Much Is Down There?

There is enough gold on the seafloor to give every person alive nine pounds, scientists estimate. That would be worth about $150 trillion, or $21,000 a person.

In the 1960s, the book Mineral Resources of the Sea predicted nearly limitless amounts of rare earth elements, forecasting a mining boom that would enrich nations and lead to rapid advancements in technology.

But that doesn't mean it's easy to access.

How Would They Actually Mine it?

Most potential mining sites are tested by sending down remotely operated vehicles (ROVs) to scrape up nodules or mineral-rich crust. Actual mining could conceivably be conducted in this way, trip by trip, but the process would be slow, and ROVs can bring up only so much weight.

A faster way would be to bring in a ship or floating platform above the mining site. Then, a conveyor belt could bring material up to the surface, where it could be sorted and separated. Another option is to use a hydraulic suction system (essentially a giant straw).

Once the valuable material is separated from the surrounding rock, the spent tailings could be dumped over the side.

A few dozen exploratory efforts are underway in deep water, by several companies. Most are in the Pacific, with a few scattered in other oceans.

The project that is furthest along has been approved for the territorial waters of Papua New Guinea, in the Bismarck Sea. Within the next few years, Canadian company Nautilus Minerals is expected to begin an experimental effort to harvest gold and copper from about 3,400 feet (1,036 meters) under the water, in a project called Solwara 1.

What Are the Potential Environmental Impacts?

The Solwara 1 project is facing opposition from some environmentalists, including the Ocean Foundation's Deep Sea Mining Campaign.

"The environmental impacts of the operation are totally unknown," campaign activist Natalie Lowrey said in a statement.

Janet Tokupep from the local Alliance of Solwara Warriors, which opposes the project, said, "Our coastal communities live only 30 kilometres [about 19 miles] from the proposed mine site and our fishermen use the area around it daily. The serious liabilities associated with the risks of Solwara 1 make it a disastrous investment."

Those groups are joined by Greenpeace in urging an international moratorium on seabed mining. They cite the experimental nature of the technology and say dumping tailings into the sea could smother sensitive marine organisms like corals, sponges, and fish. Disrupting the seafloor crust could release toxic materials such as lead or mercury. Industrial equipment could leak oil or damage reefs.

Hydrothermal vents host some of the planet's most unique creatures, including animals that exist without sunlight. Many of those organisms haven't even been discovered yet and need protection from mining, the environmental groups say.

What Regulations Are Possible?

Not all environmentalists are completely opposed to the idea of mining the deep sea, says Nugent. "We'd like to see the right safeguards in place to make sure it can be done with minimal harm," he says.

"We made a lot of mistakes in the early days of mining on land, but now we have a chance to get it right in the ocean," he adds.

In part because the seafloor is so poorly studied, nations should agree to set aside large areas that are off limits to mining, says Conn. The world's growing list of marine protected areas is a good start, but they cover only a small percentage of the total ocean.

Protecting thrity percent of the ocean is a good place to start, says Nugent.

That would provide a buffer against any damage that might result from mining and would give scientists a chance to study the impacts and compare them against undisturbed sites.

Pew would also like to see rigorous third-party oversight of deep-sea mining operations, to ensure best practices are followed in disposal of tailings, handling of toxic materials, and minimizing harm to living things.

The International Seabed Authority also needs to increase its staffing and resources and should operate with more transparency, says Nugent. Currently, most meetings on proposed sites are held in secret, making input from the public and environmental groups difficult.

The industry has countered that commercial secrets need protecting, but Nugent says it's possible to withhold sensitive data while still opening up the process to greater scrutiny.