Litter disposal and accumulation in the marine environment is one of the fastest growing threats to the world's oceans. Plastic is the most common type of litter found on the seafloor, but the list is long and includes glass, metal, wood and clothing. The EU-funded SeaClear project is developing autonomous robots for underwater littler collection using new debris mapping, classification, and collection systems. Specifically, the project will build a mixed team of unmanned underwater, surface and aerial vehicles to find and collect litter from the seabed.