Cold seeps occur where highly saline and hydrocarbon-rich fluids, such as methane and sulfides, escape into the water column from the seafloor. They are important ecosystems because the hydrocarbons often fuel entire biological communities. Chemosynthetic bacteria are able to convert the hydrocarbons into food through a process called chemosynthesis. The food produced by the bacteria is the start of a food web that often includes tubeworms, mussels, snails, crabs, and many other organisms.
To locate possible cold seep sites, explorers begin by mapping the area using a multibeam sonar and a suite of split-beam sonars which use sound waves to create an image of the seafloor and water column. The water column backscatter data collected in this process can pick up on bubbles that are released from cold seeps. After determining the general location of a seep and the depth of the seafloor, explorers can create a dive plan for the ROV to more closely examine the site. Once underwater, the ROV pilots and scientists keep their eyes peeled for bubbles and animals that are commonly found on seeps.