In which zone are the majority of the ocean species found? Why?
Generally speaking, coastal areas are very rich in marine life. In the open ocean, most life is found in the epipelagic zone.
Areas just off of the coast, from the shoreline to the edge of the continental shelf tend to have the most marine life. This area is called the neritic zone. It extends from the intertidal zone to the edge of the continental shelf where the oceanic zone begins.
Of the open ocean zones, most life is found in the epipelagic zone. This is where light is able to penetrate the ocean, allowing for photosynthetic processes to take place. It extends roughly 200m or 650 feet below the surface. This zone may also be known as the euphoric zone, the sunlight zone, or the photic zone.
It's important to keep in mind though that we have not explored much of the ocean, and the deeper you go the harder it becomes to study the different lifeforms.