Oceanic zone were created by oceanographers to make it easier to study individual ares of the oceans. They were also designed to study animals living in specific areas of the oceans.
The epipelagic, zone in the one closest to the surface and is thee best lighted zon. It extends to 200 metres and contain both phytoplankto and zooplankton that can support larger organism like marrine mammals and some types of fish.
Past 200 metres, not enough light penetrates the water to support life, and no plants life exists. There are creatures however, which thrive around hydrothermal vents, or geysers located on the ocean floor that expel super heated water that is rich in minerals.
These organis,s feed off of chemosynthetic bacteria, which use the super heated water and chemicals from the hydrothermal vents to create energy in place of photosynthesis.
The existance of these bacteria allow creatures like squid, hatchet fish,octopuses,tube worms,giant clams, spider cabs and other organismto survive.
Due to the total darkness in the zones past the epipelagic zone, many organisms that survive in the deep oceans do not have eyes, other organisms make their own light with bioluminescene.
Often the light is blue green in colour, because many marine organisms are sensiive to blue light.
