Thousands of shipping containers are lost from cargo vessels each
year. Many of these containers eventually sink to the deep seafloor. In 2004,
scientists at the Monterey Bay Aquarium Research Institute (MBARI) discovered a
lost shipping container almost 1,300 meters (4,200 feet) below the surface of
the Monterey Bay National Marine Sanctuary. In the first-ever survey of its
kind, researchers from MBARI and the sanctuary recently described how deep-sea
animal communities on and around the container differed from those in
surrounding areas.
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In February 2004, the cargo vessel Med Taipei was traveling southward
along the California coast when severe winds and seas dislodged 24 shipping
containers, 15 of which were lost within the boundaries of the Monterey Bay
National Marine Sanctuary. Four months later, during a routine research dive
using the remotely operated vehicle (ROV) Ventana, MBARI scientists discovered
one of these containers on the seafloor.
In March 2011, a research team led by Andrew DeVogelaere of the
sanctuary and Jim Barry of MBARI completed another ROV dive at the container.
During this dive, they collected extensive video footage, as well as samples of
seafloor sediment at various distances from the container. They then compared
the animals found on the container, on the nearby seafloor, and on the
surrounding seafloor out to 500 meters (a third of a mile) away from the
container. In early May, 2014 they published their findings in the journal Marine
Pollution Bulletin.
Josi Taylor, the lead author of the recent article, said that she was
surprised to see how little the container had corroded in the seven years since
it sank to the seafloor. Apparently, the near-freezing water and low oxygen concentrations
in the deep sea slowed the processes that might degrade sunken containers in
shallower water.
As expected, the hard surface of the container acted somewhat like a
rocky reef, attracting animals such as tubeworms, scallops, snails, and
tunicates. Such animals require hard surfaces on which to attach, and were not
found on the muddy seafloor around the container. Surprisingly, several types
of animals found on nearby rocky reefs, such as sponges, soft corals, and
crinoids (a distant relative of sea stars), had not colonized the surface of
the container.
The researchers speculate that some of these slow-growing animals
might not have had enough time to colonize the container’s surface. Another
possible explanation is that some types of animals may be sensitive to the
potentially toxic effects of corrosion-resistant coatings used on shipping
containers. The team conducted a follow-up ROV dive in December 2013 to study
possible effects of the container’s coating. The samples from this dive are
still being analyzed.
Read more at Monterey
Bay Aquarium Research Institute.
Underwater
shipping container image by Chad King via NOAA/MBARI.