Chuuk Pollution Traced to Sunken Tanker
When U.S. conservationist Michael Barrett began examining this issue in 2003, no one had ever mapped the wrecks precisely or done a comprehensive survey of their fuel holdings or the ecosystems they might threaten.
With funding from the National Geographic Society's Conservation Trust, Barrett was able to fill in some gaps, gathering data on 31 of Chuuk's 50-plus shipwrecks. (The National Geographic Society owns National Geographic News.)
Surveying the area by boat and from a small plane during a two-month period in 2006, Barrett often found a thin film of fuel on the lagoon's surface.
He traced one source of the pollution to a large Japanese tanker, the Hoyo Maru, which was sunk by an American bomb during the 1944 attack and now rests upside down on the sea floor.
This summer, researchers from the international environmental group Earthwatch confirmed that the same tanker, built to hold two million gallons of fuel, is still leaking oil into this ecologically rich lagoon, home to turtles, more than 200 species of fish, and at least one rare coral.
"The bubbles [of oil] come from an area the size of a dinner plate," says Australian maritime archaeologist Bill Jeffery, who led the Earthwatch team.
Earthwatch also identified a smaller oil slick coming from a nearby Japanese submarine tender, the Rio de Janeiro Maru.
The risk posed by a wreck depends on where the vessel sits, the types and amount of fuel on board, and the local environment, says Douglas Helton of the National Oceanic and Atmospheric Administration's (NOAA) Office of Response and Restoration, which evaluates and responds to many ocean hazards.
A wreck in a sensitive lagoon, for example, may pose a greater potential hazard than one that's sunk 5,000 feet underwater.
Most World War II wrecks "pose little or no threat to the environment," Lt. (j.g.) Thomas Buck, a U.S. Navy spokesperson, says via email.
"Many of the sunken WWII vessels did not, at the time of their sinking, contain large quantities of oil (i.e., the vast majority were not oil tankers); and of those that did, many no longer do, owing to the severe combat damage they sustained."
But conservationists emphasize that tankers like the Hoyo Maru deserve close watch because of their massive fuel capacity.
Most were built to hold millions of gallons of oil. And while the exact number of sunken fuel tankers is unknown, an Australian maritime consulting firm, SEA Australia, has counted 332 among the 3,700 Pacific wrecks from that era, including three in Chuuk Lagoon.
An Expensive and Complicated Problem
So what can be done about leaks from Pacific wrecks?
In the case of the Hoyo Maru, the Japanese government, which still has rights over the tanker, acknowledges local concerns and requested a Chuuk-based Japanese diver to look at the oil leaking from the tanker, "but none could be seen on the day of the inspection," Earthwatch's Jeffery says via email. "This is not unusual as it is known the tanker can exhibit leaking one day and not the next."
Overall, the small island nations of the South Pacific lack the funds and technological expertise to perform large-scale cleanups.
Even if they didn't, Japan, like the United States, and the United Kingdom, has repeatedly asserted control over the remains of its own World War II ships. All three countries say their wrecks are maritime graves and cannot be salvaged by anyone else without permission.
At the same time, they generally don't act unless they receive a specific request for help from nations affected by the wrecks.
In the U.S., where various government agencies share different kinds of authority over issues involving American shipwrecks, "Sunken wrecks are an expensive problem that many agencies feel ill-equipped and underfunded to address," NOAA's Helton wrote in a 2003 report.
While NOAA has an interest in the effects of American military shipwrecks, responsibility rests with the Navy for wrecks outside U.S. waters.
"The Navy has developed a structured case-by-case approach for dealing with situations where U.S. navy wrecks are suspected of posing undue environmental risks," says Buck.
The Case of the Mississinewa
One leaking Navy wreck that did pose risks was the U.S.S. Mississinewa, a tanker sunk in 1944 by a Japanese suicide submarine near the Micronesian island of Yap.
In 2001, the Mississinewa was jostled by a typhoon and began releasing more than 300 gallons of fuel a day on and off for a year-and-a-half.
Micronesia declared a state of emergency and temporarily banned fishing, which island residents depend on for income and subsistence.
Following a couple of patchups, the Navy organized a comprehensive cleanup in 2003 that required nine Navy commands (units), at least two barges, and approximately 15 divers who underwent at least 10 days of training beforehand.
The divers used an advanced technique called hot tapping—in which submersible hoses are attached to oil or fuel tanks and the liquid is pumped to a barge on the water's surface—to offload most of the ship's remaining oil.
Nearly two million gallons were recovered and some was re-refined and sold, recouping a portion of the $5.5 million clean-up cost.
Prevention and Assessment
Some conservationists believe assessing wrecks is the best way to avert problems.
"Prevention is always better than cure," Australian environmental scientist Trevor Gilbert says via email.
Assessing the likelihood of a spill for the highest-risk wrecks may cost hundreds of thousands of dollars, but that's certainly cheaper than the millions required to offload oil from leaking vessels like the Mississinewa, notes Gilbert, a marine pollution expert who researched the World War II wrecks for Pacific island governments and has worked extensively with SEA Australia.
Marine biologist Sylvia Earle, who spotted at least one oil leak when she first dove Chuuk in 1975 for a National Geographic magazine story, agrees it's important to assess the wrecks for environmental risk.
For each, she says, "We need to know how much oil, the depth, what the complications [of cleanup] might be. An intelligent evaluation would be mandatory."
Earle, a National Geographic explorer-in-residence, suggests starting with the Hoyo Maru: "If it's a tanker," she says, "that's a priority."
But overall Earle advocates a cautious approach. "By and large these attempts to go in and solve problems cause more problems," she says.
Still, conservationists like Barrett believe that using cutting-edge draining techniques like hot tapping on wrecks that pose the greatest risk is safer than waiting.
He hopes the data he's collected over the years will help pinpoint which wrecks are most likely to cause environmental damage—and spur cleanup efforts. In the meantime, he continues to worry about the effects of the Hoyo Maru and other World War II wrecks: "The longer these ships are down there corroding or getting battered by waves," he says, "the higher the risk of a spill."
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