Thursday, March 10, 2011

The secret life of a container lost at sea

From NewScientist

Over in California's Monterey bay, an unusual three-day cruise kicked off today.
Marine biologists there are investigating what happens to sea-floor ecosystems when
shipping containers are accidentally shed from cargo ships.
With 10,000 containers lost at sea each year, that's a less trivial question than it might seem at first glance.

The project is the result of chance discovery of one such container - plus a legal settlement which resulted in the US government receiving $3.25 million to compensate for the pollution of a national marine sanctuary.

On 25 February 2004, the
container ship Med Taipei was caught in 9-metre swells off Monterey bay in central California, heading south for the port of Los Angeles
That night, 15 of its containers broke free of their lashings and toppled into the sea.
Their contents included wheelchairs, cyclone fencing, clothing and recycled cardboard.

That would have been the end of the story, had the
remote controlled submersible Ventana, operated by the Monterey Bay Aquarium Reseach Institute (MBARI) in Moss Landing, not happened across the container in June 2004.
Video footage clearly showed the container's serial numbers, which was key to extracting the record-setting
payment from the Med Taipei's operators - All Oceans Transportation, Italia Marritema and the Yang Ming Transport Corporation.

This shipping container was discovered upside down on the seafloor by MBARI researchers in June 2004, four months after it was lost at sea.
Researchers will revisit this site during the upcoming cruise.
Image: © 2004 MBARI

Some of the money is now being used to allow scientists from MBARI and the Monterey Bay National Marine Sanctuary (MBNMS) to see what has happened to the ecosystem since the 10-metre-long container landed on the seabed.

The container is lying in 1300 metres of water.
Like most of the deep ocean, the seabed at the site is soft and muddy.
While the 2004 video shows the container looking pristine and uninhabited, it may since have been colonised by species including sea anenomes and deep sea corals, and provided a habitat for fish generally found near rocky reefs.

This map shows the reported position of the container ship Med Taipei when it lost lost 15 containers overboard on February 26, 2004.
It also shows where one of these containers landed on the seafloor, just outside of Monterey Bay.

Introducing an artifical reef might sound like a positive result, but the colonisers could also include predators of the snails, sea cucumbers, brittle stars and other species that live on the muddy bottom - much in the same way as introducing a tree into an upland area can be threaten local rodents by providing a perch for birds of prey.
"You're establishing a new habitat for species to base their foraging from," says
James Barry, a senior scientist at MBARI.

While this particular container was carrying a relatively benign cargo of tyres,
Andrew DeVogelaere, research co-ordinator for the marine sanctuary, warns that other containers are used to transport toxic materials.
And with some 10,000
containers being lost at sea each year, they may also provide "stepping stones" along shipping routes, facilitating the spread of invasive species that prefer hard-surfaced habitats.

DeVogelaere and his colleagues will explore the container with a newer remotely operated vehicle, the
Doc Ricketts.
They will count deep-sea animals on the container and the surrounding seabed, use the submersible's robotic arm to capture those that need to be identified in the lab, and take samples of the sediment for biological and chemical analysis.

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