A Complex Food Chain

In a cold-seep community a third of a mile down in the Gulf of Mexico, the orange mat in the foreground is a colony of microbes that live on oil and gas seeping up from the seabed, starting a complex food chain that results in a dark ecosystem. In the background are tubeworms, which can grow eight feet long and live for centuries. Near the tubeworms are snail and clam shells, which appear to be empty.