They are decomposers that eat the dead or decaying matter in the ecosystem.
Community one because there are more different types of species and less of them.
Since oceans cover 71% of the Earth’s surface, understanding what the seafloor looks like, and where different processes, such as ocean currents are active, is hugely important. Mapping the seafloor helps to work out things like where different types of fish live, where resources may be, such as rare metals and fossil fuels, and whether there is a risk of underwater landslides happening that might cause a tsunami. Mapping the seafloor is very challenging, because some cannot use the same techniques that some would use on land. To map the deep ocean, there's a tool used called a multibeam echo-sounder, which is attached to a ship or a submarine vessel.
