In its
hefty report on the state of the oceans and federal ocean policies, the U.S.
Commission on Ocean Policy suggested setting a course for using the oceans to
farm fish, not just catch them. The Bush administration seized upon this notion,
calling for a sustainable plan to increase mariculture — offshore marine
fish farming. One option is to use the thousands of oil and natural gas platforms
that line the nation’s coasts as staging areas for the farms. Although
fish farming in federal waters is not yet a commercial reality, many in industry
and government are forging ahead with mariculture plans.
Net pens (in the foreground) established
around oil platforms, such as this one in the Gulf of Mexico, can hold up to
150,000 pounds of fish. New energy is being put into the effort to convert oil
and natural gas platforms into staging areas for fish farming. Courtesy of NOAA.
A primary driver for the push toward mariculture is increased consumption of
fish in the United States, says Michael Rubino, aquaculture program manager
for the National Oceanic and Atmospheric Administration (NOAA). “We already
import close to 70 percent of our seafood,” he says, with U.S. imports
accounting for $7 billion annually in trade deficits, a number that is projected
to rise.
“We’ve already wiped out the major stocks of big fish in the ocean
and are beginning to deplete the smaller-sized stocks as well,” says Paul
Sammarco with the Louisiana Universities Marine Consortium, which conducts marine
research and education activities in Louisiana. Other countries, such as Japan,
are building platforms offshore specifically for mariculture, he says. The United
States already has the highest density of offshore platforms, which are much
more substantial in structure and of much higher value, he says, “so why
not put them to new use?”
The majority of U.S. offshore oil and gas platforms are in the Gulf of Mexico,
where 3,600 platforms are scattered up to several hundred miles offshore. Most
of the platforms are currently active. Under current legislation, once a company
stops producing oil or gas from a platform, they have about a year to decommission
and remove it, Sammarco says. It costs oil companies anywhere from $2 million
to $30 million to decommission and remove platforms, says Granvil Treece with
NOAA’s Sea Grant program in Texas, depending on a platform’s size
and distance from shore. It would cost significantly less, he says, to leave
the platforms in place even if they are decommissioned.
Removing the platforms would also represent a loss of reef communities that
have developed on and around these artificial reefs, Sammarco says. The Gulf
of Mexico alone contains 3,600 thriving platform reef systems. “By volume,
these are the most productive ecosystems on the planet.” Turning the platforms
into home bases for fishing would save the oil companies money, while preserving
the ecosystems, Sammarco says.
Like offshore oil workers, fish farmers could sleep on the platforms, and food
and equipment for the fish farms could be stored onboard, says James McVey,
aquaculture program manager for the National Sea Grant College Program. The
platforms also could be used as hatcheries, he says. The average-sized platform
could support at least four 3,000-cubic-meter net pens, which can each contain
100,000 to 150,000 pounds of fish.
Mariculture is already a reality in state waters, where permitting processes
are in place, McVey says. Fish are commercially grown in Hawaii, Puerto Rico
and New Hampshire, for example — though not using oil platforms as bases.
Where fish are currently farmed, scientists have been studying environmental
impacts, including monitoring the waters above, below and 100 meters away from
a net, and checking the sediments on the seafloor below for fecal contaminants
and nutrient levels. Their research has shown that as long as fish farms are
sited properly, contaminants do not cause significant environmental change.
But environmental groups have concerns about the long-term effects of large-scale
mariculture. With regard to oil-platform use, for example, Catherine Hazlewood
of The Ocean Conservancy points to pollutants such as barite that are associated
with oil rigs. She says that unless the oil companies are required to decommission
the rigs as current law dictates, these toxins will remain in the water. Current
legislative proposals do not force the oil companies to decommission the platforms
or restore the surrounding ecosystems, they simply release liability for the
oil company and transfer ownership to a new owner or user. Other concerns relate
to mariculture as a whole, such as the possibility of disease or parasites spreading
from farmed fish to natural fish.
But McVey says that “we have enough information to provide best management
practices for mariculture.” Additionally, the National Marine Fisheries
Service has already developed a code of conduct for responsible fish farming,
as has the U.N. Food and Agriculture Organization.
NOAA is working on a bill to set up a regulatory process to allow mariculture
options to move forward, Rubino says. The president hopes to send a mariculture
bill to Congress sometime this year.
Megan Sever
Links:
NOAA
Fisheries
NOAA
Sea Grant
Rigs-to-Reef
Committee
on Ocean Policy
The
Ocean Conservancy
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On March 30, Royal Dutch/Shell announced that the company would reroute an
oil and gas pipeline they were building for developing an oil field off the
Russian island of Sakhalin, after receiving pressure from environmental groups.
Where they had originally planned to route the pipeline ran too close to feeding
grounds of the endangered western gray whale, according to the World Wildlife
Fund.
According to the Associated Press, Shell said it had stopped laying the pipeline
in April 2004, following its own research that showed the pipeline could harm
the whales. The company is awaiting approval from the Russian government for
a new pipeline route.
Michael J. Magyar, the rhenium commodity specialist for the U.S. Geological Survey, has compiled the following information on rhenium, a rare metal used in turbine blades and catalysts.
Rhenium, an exotic, heat-resistant metal, has grown in importance since its
discovery nearly 80 years ago. First isolated by a team of German chemists studying
a platinum ore, the mineral was named for the Rhine River. From then until the
1960s, only 2 metric tons of rhenium were produced worldwide. In 2004, worldwide
production was 40 metric tons.
Its high melting point (3,180 degrees Celsius) and heat-stable crystalline structure
make rhenium an excellent refractory metal. Metallurgical applications are now
the single biggest market for rhenium (about 60 percent).
In the late 1960s and early 1970s, rhenium was used in rocket thrusters, which
reach temperatures of up to 2,230 degrees Celsius. Other early uses included
filament wires in mass spectrographs and flashbulbs, and anodes of X-ray machines
and thermocouples. In the early 1970s, Chevron Corp. developed a series of platinum-rhenium
catalysts that would not react with sulfur to assist in the production of lead-free
gasoline at oil refineries. As a response to the OPEC oil crisis in the 1970s
and early 1980s, a second generation of more efficient catalysts was developed
with double the platinum-rhenium content, boosting refinery efficiency and octane
levels.
Since the late 1980s, rhenium’s main use has been in nickel-base superalloys
to make single-crystal turbine blades. The rhenium allows turbine engines to
be designed with closer tolerances for increased thrust and high operating efficiency.
Jet-engine turbines now account for 45 percent of U.S. consumption of rhenium.
Increased rhenium consumption is forecast for the next generation of fighter
jets, the F-22 Raptor and the F-35 Joint Strike fighter, as well as in new gas-fired
turbines for power generation.
Rhenium is one of the rarest and most dispersed metallic elements in Earth’s
crust, with abundance estimated to be about 1 part per billion. Although traces
of rhenium occur in some minerals, molybdenite is the only significant host
mineral.
Most of the world’s reserves of rhenium are found in the Western Cordillera
of North America and South America, extending from Alaska and British Columbia
through the United States and Central America to the Andes Mountains of Peru
and Chile. Other rhenium-bearing sedimentary copper deposits are located in
Kazakhstan and neighboring countries. Chile and the United States possess about
75 percent of the world’s reserve base of rhenium.
Chile, Kazakhstan and the United States (in descending order) provided most
of the world’s production of rhenium in 2004. Molibdenos y Metales (Molymet),
a private company in Santiago, Chile, produces about half of worldwide production.
Molymet processes concentrates from mines in Chile and Peru, but does not own
any mines.
The United States’ share of world production in 2004 was 12 percent, about
the same as in 2003; however, the United States presently consumes about 75
percent of world’s rhenium production.
Visit minerals.usgs.gov/minerals
for more information on rhenium.
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