Neritic zone

The neritic zone is a vital part of the global ocean system. It is the relatively shallow area located above the continental shelf. Some scientists also call this the sublittoral zone or the coastal ocean. This region is important because it serves as a meeting point. It is where the oceanic system interacts directly with the land and coast.

Because it is shallow, it provides a stable environment for a huge variety of life.

The most important feature of this zone is sunlight. Sunlight can reach all the way down to the ocean floor here. This area of light is known as the photic zone. In most cases, light can penetrate through the water about 100 meters deep. This depth is about 328 feet. When light reaches the benthic zone, which is the ocean floor, it allows life to thrive. This light is the engine that drives the entire ecosystem through photosynthesis.

Marine biologists divide the neritic zone into several specific layers. First, there is the infralittoral zone. This area is dominated by algae and extends to about five meters below the low water mark. Next is the circalittoral zone. This region is further out and is home to sessile animals. Sessile animals, such as oysters, are organisms that stay in one place. Finally, there is the subtidal zone. This part of the neritic zone is always underwater and is never exposed to the air.

Physical oceanographers study the zone for its movement and energy. They look at how the water behaves near the coast. This includes significant tidal flows and the way energy dissipates. They also observe internal waves and ocean fronts. River outflows also enter this zone, bringing new materials into the coastal waters. These physical forces help shape the environment that marine life inhabits.

The physical conditions in the neritic zone are ideal for life. The water is generally well-oxygenated and receives plenty of sunlight. Temperatures remain relatively stable in this region. Additionally, the water pressure is low compared to the deep ocean. The salinity, or the amount of salt in the water, also stays stable. These factors create a perfect setting for high primary production. Primary production is the process where organisms create energy from sunlight.

This high energy production supports a massive food web. It begins with photosynthetic life like phytoplankton and floating sargassum seaweed.

Tiny creatures called zooplankton then feed on the phytoplankton. These zooplankton include microscopic foraminiferans as well as small fish and shrimp. These two levels form the base of the food chain. This process ultimately supports most of the world's great wild fisheries. Corals also thrive here because the environment is more stable than the intertidal zone. The neritic zone can reach depths of about 200 meters, or 660 feet.

The size and shape of the neritic zone can change depending on the geography. Some coastal areas have very long stretches of shallow water. These areas extend far out from the landmass into the sea. However, other places have very short neritic zones. For example, islands formed from ancient volcanoes often have very steep edges. In these cases, the continental shelf drops away quickly. This means the shallow, sunlit area is much smaller than in other parts of the world.