Final answer:
The 'graveyard' of the marine environment refers to the deep ocean bottom, which is primarily inhabited by small point scavengers, such as marine flatworms, that consume dead organic matter.
Step-by-step explanation:
The marine environment often called the 'graveyard' is the deep ocean bottom. This area is considered a graveyard because it is inhabited by only small point scavengers and not the larger marine animals typically found in more biodiverse ecosystems like shallow ocean environments. These scavengers, like certain marine flatworms, consume the soft tissues of dead animals that sink to the ocean floor, as larger predators and prey are not present in this extreme environment.
Marine ecosystems consist of three basic types: shallow ocean, deep ocean water, and deep ocean bottom. Each of these ecosystems plays a unique role within the marine biosphere. The deep ocean bottom is less diverse than shallow waters and deep ocean waters but is an essential part of the marine ecosystem. It is where tiny sea plants and animals, once dead, are buried by layers of silt and sand over time.
Human activities such as bottom trawl fishing can profoundly disrupt the functioning of marine ecosystems by destroying bottom fauna. The schematic representation of the 'fishing down marine food webs' process demonstrates the shift in fishing efforts from large, more complex organisms to smaller species as the larger ones become depleted.