Lost CargoCrabs and deep-sea snails crawl on a sunken shipping container that's giving scientists a rare opportunity to study marine debris up close.Pictured in December 2013, the 40-foot-long (12-meter-long) container is one of 15 that fell off the cargo ship Med Taipei on February 26, 2004, when she encountered rough waters off Monterey Bay, California (map).A few months later, scientists with the Monterey Bay Aquarium Research Institute (MBARI) happened upon the structure while checking on other experiments about 4,200 feet (1,280 meters) deep in the Monterey Bay National Marine Sanctuary.It proved a valuable discovery: No one knows how the estimated 10,000 containers that are lost in the ocean every year affect the environment. (See: "Pictures: Surprising Amount of Trash Found on Deep-Sea Floor.")"We're fortunate enough to be in the unique position to study one container," which holds 1,159 steel-belted tires, said Andrew DeVogelaere, the sanctuary's research coordinator.DeVogelaere and team, who studied the container for the first time in March 2011, recently went for another look, accompanied by MBARI biologist James Barry.The team surveyed the animals living on and around the container, gathered sediment to test for toxins leaching from the container, and visited an unexplored portion of the ocean.Barry said he noticed more animals living on the sunken object now than in 2011, but he thinks the low-oxygen environment will limit any more arrivals.The low oxygen has also kept the container from degrading, so it's hard to tell that the container has been underwater for almost a decade."It's only starting to rust in places where it was damaged, maybe where it fell off [the ship]," DeVogelaere noted."I'm thinking these containers could be down there for centuries."—Melissae Fellet

Photograph by NOAA/MBARI