What lives on a shipping container under the sea? Tubeworms, scallops, snails, and tunicates!
Shipping containers are the red blood cells of the world economy—shuffling 90 percent of nonbulk goods from where they're made to where they're consumed. There are 5 to 6 million—maybe more—shipping containers riding across the world's oceans at the very moment you're reading this. And at an estimated average of once an hour, one of those shipping containers falls into the ocean and is never seen again.
Sometimes this is big news—like when 520 fell off the Svendborg Maersk in February, or in 1990 when four shipping containers fell off a ship and released 61,280 Nike sneakers to the ocean currents, coughing them up hundreds of miles away in the North American Pacific Northwest. But most of the time it's written off as the cost of doing business. What happens at sea, stays at sea, and so long. It's a big ocean and not something that the companies really even have to report.
A decade ago, in February 2004, the Med Taipei was traveling southward from the Port of Oakland, along the California coast, when severe winds and the sea dislodged 24 shipping containers from the cargo ship, which dropped 15 of them within the boundaries of the Monterey Bay National Marine Sanctuary. Ah, well, bad luck.
Four months later, though, during a routine research dive using a remotely operated vehicle (ROV) Ventana, scientists from the Monterey Bay Aquarium Research Institute (MBARI) discovered one of these containers on the seafloor, 4,200 feet below the surface. As its a national marine sanctuary, the shipping company responsible was sued for $3.25 million in compensation. The MBARI research team found a silver lining and used the lost shipping container as a sort of case study. How does the ocean ecosystem adapt to an intrusion from above?
Animals on the sunken container included tubeworms (hanging off the side of the container) and Neptunea snails, which laid eggs in columns along the edge of the container.Image: © 2011 MBARI / NOAA, used with permission
As anyone who has seen underwater shipwrecks can tell you, the ever-vital ocean can make habitats of what its given, which is why things like old subway cars, aircraft carriers, and tanks make for viable artificial reefs. Still, that doesn't mean that submerged shipping containers are a desirable outcome.
Apart from the contents not making it to their destination—be it shoes, or in the marine sanctuary, steel belted radial tires—shipping containers, especially well-sealed refrigerated ones, sometimes become low-lying artificial icebergs, and hazards for other ships.
Sometimes their contents contribute the growing clouds of the artificial flotsam and jetsam made of floating ocean garbage, or the sunken ocean garbage litter the ocean floor. Sometimes the escaped contents are something like batteries or pesticides, and hazardous to their new ecosystem. Sometimes the outsides of the containers themselves are, covered in toxic anti-corrosive paint.
Image: © 2014 MBARI, used with permission
In March 2011, a research team from MBARI completed another ROV dive at the container. During this dive, they took the footage that became the video seen above. Josi Taylor, the lead author on the findings published in the Marine Pollution Bulletin, said that she was surprised to see how little the container had corroded in the seven years since it sank to the seafloor. The near-freezing water and low oxygen concentrations in the deeper sea seems to have slowed the processes that might degrade sunken containers in shallower water.
But it was no surprise that the shipping container was functioning much like a rocky reef. Animals that require hard surfaces to attach to—the tubeworms, scallops, snails, and tunicates—weren't able to live on the muddy seafloor around the container, but they were getting tony locales on the container.
As a testament to the pace of life on the seafloor, sponges, soft corals, and crinoids, found on nearby rocky outcrop, hadn't moved onto the container yet, although the zinc-based paint might also be to blame there. Another diving drone was sent down in December, and the results are forthcoming.