Lost shipping container shown to effect on sea life

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 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 institute and the sanctuary described how deep-sea animal communities on and around the container differed from those in surrounding areas.

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 Ventana, scientists discovered one of these containers on the sea floor.

In March 2011, a research team led by Andrew DeVogelaere of the sanctuary and Jim Barry of the institute completed another remote dive at the container. During this dive, they collected extensive video footage, as well as samples of sea floor sediment at various distances from the container. They then compared the animals found on the container, on the nearby sea floor, 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 sea floor. Apparently, the near-freezing water and low oxygen concentrations in the deep sea slowed the processes that might degrade sunken containers in shallower water.

The animals growing on the sunken shipping container were quite different from those growing on the surrounding sea floor.

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 sea floor 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 believe the container is having indirect ecological impacts, some of which may take years or decades to develop. For example, higher numbers of sea floor predators near the container might explain some of the changes in the types of other animals found on the nearby sea floor. Such indirect ecological effects might also explain why the diversity of sea floor animals was lower near the container.

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