The deep sea is the last great frontier on Earth. For hundreds of years people have pondered, debated and explored the vast depths of the oceans, yet our knowledge of them barely skims the surface. Remarkably, though it is the largest ecosystem on Earth, we have better maps of Mars than we do of our own planet's seafloor. The deep ocean is no longer unspoiled wilderness. Improved technologies have allowed the expansion of some of our activities into the deep sea. By far the largest current threat is from destructive commercial fishing practices. Likened more to clear-cutting than fishing, destructive trawling in particular has caused considerable damage to deep sea communities on the continental slope and on undersea islands called seamounts. Trawling can destroy centuries of coral and sponge growth in a single pass, and pulls to the surface myriad unwanted animals that are simply thrown back dead or dying. Unfortunately, few laws and regulations protect deep sea communities from bottom trawling. Virtually no protections at all exist on the high seas – two thirds of the entire ocean – because they fall outside the jurisdiction of any national government.