The abyssal zone is a dark and deep region of the ocean, typically situated at depths ranging from 2,000 to 6,000 meters (6,500 to 19,500 feet). This zone is characterized by low temperatures, around 4°C (39°F). The majority of the deep-ocean floor, approximately three-quarters of its total area, lies within the abyssal zone.
The abyssal zone is located too far from the ocean surface for photosynthesis to occur, as sunlight cannot penetrate to these depths. Consequently, the abyssal zone is known for its lack of sunlight, making it one of the least illuminated regions in the ocean. Despite the challenging conditions, certain organisms, such as fish and crustaceans, have adapted to life in the abyssal zone. Some of these deep-sea creatures may be blind, while others possess their own bioluminescent light sources.
Above the abyssal zone is the bathyal zone, and below it lies the hadal zone. These oceanic zones collectively contribute to the vertical stratification and ecological diversity of the marine environment.