The marine minerals industry is dwarfed by the $100-billion-dollar-a-year offshore oil and gas industry. However, much of the technology (such as the work class ROV pictured here) that enables the commercial search for minerals finds its origin in the offshore oil industry. Dr. John Wiltshire of the University of Hawaii gives us an overview on the state of today's marine minerals industry, and what might be around the corner.

The extraction of marine mineral resources represents just under a two billion dollar per year industry worldwide. There are approximately a dozen general types of marine mineral commodities, about half of which are presently being successfully extracted from the ocean. These include sand, coral, gravel, and shell for aggregate, cement manufacture and beach replenishment; magnesium for chemicals and metal; salt; sulfur for sulfuric acid; and placer deposits for diamonds, tin, gold, and heavy minerals.

Deposits which have generated continuing interest but are not presently mined include manganese nodules and crusts, polymetallic sulfides, phosphorites, and methane hydrates. Each of these mineral commodities is represented by a separate industry, which responds to local pressures and opportunities in its own geographic area. Recent areas of success include rapid expansion of the diamond industry off the southwest coast of Africa, expansion of the offshore sand and gravel industry for beach replenishment and construction aggregate, new industry interest and leasing of polymetallic sulfide deposits, and significant interest in the possible recovery of methane hydrates.

Commercial Viability: Diamonds, Sand, and Gravel
The commercial successes of the marine minerals industry in the last five years have been in sand and gravel and offshore diamonds. Off the southwest coast of Africa, primarily Namibia, the offshore diamond industry now works down to 656 feet (200m), with leases extending to 3,280 feet (1,000m) depth.

More than a dozen mining vessels are now involved in this expanding industry, many equipped with sophisticated underwater robotic miners such as the Tramrod and Namrod. De Beers Marine, one of the leaders in this field, has purchased an M600 AUV from Maridan in Denmark to conduct remote underwater surveys for new prospects. Another company is experimenting with new techniques to sieve diamond gravels underwater to reduce the amount of material to be transported. The quality of diamonds coming from the offshore sector is proving superior to those found at many onshore sites because of natural sorting processes. Many of the operators are noting the advantages of larger equipment which can be used offshore compared to a restricted mine shaft environment, as well as the absence of infrastructure costs, such as shafts and rail lines, which cannot be moved once a new mining location is selected. Over the next five years we are likely to see more expansion with increased technical sophistication in all aspects of this very profitable industry.

At the other end of the value spectrum from diamonds is sand and gravel. In the U.S., significant amounts of offshore sand have been dredged and placed back on beaches in beach replenishment programs. While expensive, this is proving to be the most effective way to handle beach protection.

In the U.S., it is possible to use sand, gravel, and shell resources from federal waters (generally beyond three miles offshore) for shore protection, beach restoration, or public works projects without a competitive lease sale. This has resulted in significantly increased offshore sand and gravel activity. There are more than a dozen large offshore sand projects on the U.S. East and Gulf Coasts ongoing or pending approval. All of the projects use standard dredging and beach replenishment techniques. Many of the newer dredges involved in these operations are very heavily automated, mine high volumes of sand and aggregate, and offer the ability to move significant quantities of material several miles in high capacity pipe. The technology involved in this industry is being continuously upgraded, with innovative new developments incorporated from European experience and the offshore oil pipeline trenching industry. For smaller projects, new highly efficient truck transportable dredges and even high capacity hand-held jet pumps allow the movement of smaller amounts of sand with great control at low cost.

Deepwater Hydrothermal Vents
With respect to deeper water minerals, commercial interest has shifted to polymetallic sulfides (deposits at inactive hydrothermal vent sites) from manganese nodules and crusts.

The government of Papua New Guinea has issued two leases on deposits in the Manus Basin south of New Guinea. Leases off Fiji are in the planning phase. The sulfide deposits involved are rich in gold and silver, and are in less than 6,560 feet (2,000m) of water. There are several small mining groups in the U.S. and Australia, including Deep Sea Minerals and Nautilus Minerals, in addition to Phelps Dodge, that have expressed interest in these deposits. Exploration cruises have taken place, environmental plans formulated and some consideration given to the mining technology. To date there have been no equipment tests. While the prime economic targets will be gold and silver, possible secondary targets include zinc, lead, and copper. The studies of economic potential look promising. If these companies are able to raise the necessary capital, mining operations could begin within a decade.

The most significant development in deep sea minerals could be methane hydrates. This gas, frozen on the deep sea floor, has the potential to be one of the greatest untapped energy resources on the planet. A $60 million dollar Japanese research program is currently focused on investigating this resource and, for the first time, is trying to develop ways of commercially extracting the resource. A somewhat smaller U.S. program is also being coordinated through the Department of Energy. While little engineering information has been released from these programs, it appears from early reports that the extraction of methane hydrates may be technically feasible.

The successful commercialization of this kind of a deep seabed, high value mineral resource would have a profound effect on the development of other seabed resources and, for that matter, all seabed projects requiring new technology to work at these depths.

Advanced Technology Aids Development
Several trends are pushing forward development of many types of marine minerals. These include:

1. the outstanding success of both the deep water oil industry and the offshore diamond industry,
2. off-the-shelf technology capable of 6,560 feet (2,000m) depths,
3. the increasing wealth in the western world and more tolerance of high risk ventures,
4. growing world population with ensuing metal demands causing metal prices to rise,
5. growing environmental consciousness, which makes new mines on land difficult to open,
6. rapid advances in robotics, GPS, marine biotechnology, and Web-based control systems, and
7. a stable international regime and Law of the Sea environment.

The combined result of these seven trends is, in general, a very favorable environment for the development of marine minerals.

Another major player in the changing face of marine minerals technology is the deep sea cable laying industry. With the exploding growth of the internet, this $10 billion per year industry is expanding and developing a whole new set of equipment designed to cut and trench into the bottom and lay cable. This equipment is capable of cutting trenches to 6.6 feet (2m) depth in 6,560 feet (2,000m) of water.

To adapt such equipment to mine diamonds, polymetallic sulfide mounds, or manganese crusts requires only the change of a cutter head and the addition of an airlift (the best developed marine minerals technology). Of particular significance in this regard are the new generation of heavy tracked bottom crawling vehicles and the new class of vehicles combining ROV flexibility and manipulator systems with the possibility of adding tracks.

On a wider front, a whole range of new lower cost and higher efficiency marine technologies is making the marine minerals industry more cost competitive. Over the next ten years these will significantly change the face of the industry. Accurate low cost positioning systems using sophisticated GPS units have made it possible to very precisely locate the deposits and position equipment. One survey company has just released a long range, real-time kinematic positioning system with 20cm horizontal and vertical accuracy over 800km distances. Multibeam bathymetric mapping systems now allow rapid highly accurate coverage of large bottom areas.

For sulfide deposits, new 10,000 feet (3,000m) depth rated electric work ROVs with two highly controllable manipulators are presently available off the shelf and can be run from a six-foot screen at a theater view control station. AUVs are presently available for contract, equipped with side scan sonar and sub-bottom profilers for exploration. Other significant innovations include GPS navigation systems connected to underwater acoustic transponders, improved underwater communications systems, linked satellite and buoy technology, marine leach mining systems, affordable dynamic positioning, high resolution chirp sonar, fast stable ship technologies including swaths and mid foil designs, low cost floating platforms and new high tech metal and ceramic alloys. These technologies are being incorporated into every aspect of offshore mineral exploration, production, and transportation. They are dramatically reducing costs and increasing the competitive advantages of the offshore producer.

Manganese Nodules and Crusts Still Years Away
In spite of these technical advances in a range of key support industries, the full development of manganese nodules and manganese crusts is still probably a minimum of 20 years away. One of the major reasons given for the slowness in the development of manganese nodules has been the alleged failure of the Law of the Sea Treaty to adequately protect seabed mining interests. The U.S. has renegotiated Part XI of the Treaty which was considered to be the problem area. Many of the concerns raised by industry have been addressed in this revision, even if not fully solved to the satisfaction of every company.

The Law of the Sea Treaty came into full effect in November 1994. However, the strong resistance of U.S. Senator Jesse Helms (Republican, North Carolina) to the Law of the Sea Treaty will likely prevent the U.S. from agreeing to the treaty any time soon.

In the meantime, the United Nations International Seabed Authority published Draft Regulations on Prospecting and Exploration for Polymetallic Nodules in August 1999. This 49-page document outlines standard requirements and methods for applying for permits to allow exploration. The document represents a good first step toward regulating a future nodule industry. The International Seabed Authority has recently begun work on regulations for other seabed minerals. There are active government-backed nodule programs in Korea, China, and India, as well as a less active eastern European program. The program in Korea has suffered under the Asian financial crisis but continues to move forward, recently awarding a contract to the University of Hawaii's mapping research group to demonstrate a sonar mapping capability for quantifying manganese nodule deposits. The program in China has suffered a similar fate, in addition to a reorganization of government ministries which reduced the political access of the group.

If Asia goes back into a period of economic boom it is likely that these programs will be scaled up, as the fundamental forces driving them have not changed. Particularly significant here will be the increase in disposable income of families in China and India. This is one of the reasons that the government of China is so interested in a marine minerals industry. To supply the quantities of metals required will necessitate many new sources to be developed. Harvesting these minerals from the ocean will also allow a major new domestic high tech ocean industry to come into being. Equipment and expertise developed for a national deep ocean mining industry will have a variety of other spin-offs for a wide range of other deep ocean applications, including marine biotechnology.

Nickel, copper, and cobalt are the prime economic targets for manganese nodules. Cobalt, nickel, manganese, and platinum are the prime economic targets for manganese crusts. Nickel and cobalt prices are currently high (by historical standards), with copper prices moderate. These prices had been depressed in the early 1990s. With prices in this range, new leach mining systems for manganese crusts cost out very favorably at over 30 percent internal rate of return.

Nonetheless, U.S. industry has generally been reluctant to pursue this new opportunity. Why is this? It is largely a perception of risk. For most companies in the minerals business, working in the ocean is an unknown area and clearly an area where some technical failures are both likely to occur and difficult to manage.

High cobalt prices are also encouraging others into the cobalt mining environment. If too many large land based projects come on line, then the price of cobalt will go down. It is likely that a marine mining venture would have a higher cost of production than a new large terrestrial deposit. In fact, such a deposit is under development at Voisey's Bay, Labrador, by the International Nickel Company (INCO). If this deposit comes on line, as expected, in the next decade it will dominate both the nickel and cobalt markets. Initial estimates are that control of this one deposit will increase INCO's share of the world nickel market to 40 percent.

Several major new cobalt deposits are also rapidly being developed in Australia. This is shifting the balance of the cobalt mining industry from Zambia and Zaire in Africa to Australia and Canada. This will likely bring some price stability to the market, with prices possibly lower for cobalt than those experienced today. At the same time, new high tech uses are causing the world market for cobalt to grow at 5-8 percent a year. The development of electric or hybrid gas-electric cars would greatly spur cobalt demand, as cobalt is a major component of high capacity batteries.

Marine Biotechnology
A new interest on the scene is marine biotechnology. The search for deep sea organisms, particularly hydrothermal vent bacteria, is the new mecca for the marine miner. These are used by drug companies and industrial process engineers to provide genetic material which can be altered for industrial usage. Some of these organisms can survive on the seafloor in temperatures up to 350 degrees centigrade and immense pressure. Living catalysts able to stand these sorts of pressures and temperatures would foster a wide range of industrial processes, including some not presently economically or technically feasible. The drugs which can be extracted from deep sea organisms also are exceptionally valuable because of the extreme potency of many marine toxins, useful in the fight against cancer. Submersibles and ROVs are used to collect these materials from the sea floor. They are then processed through labs and sent to the commercial sector. The U.S. National Science Foundation has just begun the Marine Bioproducts Engineering Center at the University of California, Berkeley, and the University of Hawaii.

Increased Demand for Ocean Minerals
If current trends hold, world economic growth is likely to continue. The demand for construction aggregate will cause expansion in the offshore sand and gravel industry. The success of the offshore diamond industry will likely result in expansion to new areas already under consideration, such as off the northwest coast of Australia and Northern Canada. New technology may make the companies now considering polymetallic sulfides feel the risk is closer to palatable. Increased amounts of research and development money will flow toward the commercialization of methane hydrate and marine biotechnology discoveries. Government mining groups in Asia are already upgrading their manganese nodule and crust programs to address increased mineral demand.

It is likely that these efforts will continue and perhaps even expand, but unlikely that any commercial development will occur in manganese nodules or crusts for a least 10 and probably 20 years.

In summary, the marine minerals industry is alive and well. Significant resources of a wide range of minerals exist and are becoming more attractive. New cheaper and more efficient marine technologies are moving into every aspect of mineral exploration and processing. Within a decade or two, these may be anticipated to lead to a major expansion of this industry and a move into deep water. UW
Dr. John Wiltshire graduated in 1976 with a B.S. in geology from Carleton University in Ottawa, Canada. He worked as an exploration geologist in the oil and mining industries for Noranda Mines, Chevron and Petro-Canada. Dr. Wiltshire earned a Ph.D. in Geological Oceanography from the University of Hawaii in 1983. He then became Ocean Resources Manager for the State of Hawaii in the Department of Business and Economic Development and Chief Geologist of the State of Hawaii's Marine Minerals Program. In 1986, he joined the Hawaii Undersea Research Lab as a senior researcher, becoming Associate Director in 1990.
Dr. Wiltshire is also an advisor to the U.S. Secretary of the Interior on offshore oil, gas, and minerals leasing as part of the Outer Continental Shelf Policy Advisory Committee. He is a member of the graduate faculty of the University of Hawaii's Department of Ocean and Resource Engineering. He is also a fellow of the Marine Technology Society and is the author of 70 scientific papers, primarily dealing with marine minerals, mineral economics and mine tailings. Reprinted courtesy of the Marine Technology Journal, Volume 34, Number 2.