Final answer:
The neritic zone has the highest productivity in the ocean due to factors such as silt-rich water, well-oxygenated conditions, and stable temperatures. Phytoplankton, zooplankton, and small fishes play a significant role in supporting the food chain and fisheries in this zone.
Step-by-step explanation:
The neritic zone, which extends from the intertidal zone to the edge of the continental shelf, has the highest productivity in the ocean. Several factors contribute to this productivity, including silt-rich water, well-oxygenated and stable temperature conditions. These conditions support the growth of phytoplankton, photosynthetic bacteria, and larger algae species, which are responsible for the primary productivity in the neritic zone.
Zooplankton, protists, small fishes, and shrimp feed on the producers and serve as the primary food source for most of the world's fisheries. The majority of these fisheries thrive within the neritic zone, making it a crucial area in maintaining marine biodiversity and supporting the oceanic food chain.