In the ocean why are the greatest amount of primary producers found in the epipelagic zone and how does that affect biodiversity

The Epipelagic zone has the warmest water and the highest rate of gas exchange with the atmosphere, which increases biodiversity.

Explanation:

The epipelagic zone is the surface layer of the ocean which extends to up to 200 meters and it is the layer that is exposed to the atmosphere and hence, the exchange of gases takes place in this layer.Most of the visible light is available to the organisms living in this layer and thus, the water in this zone is the warmest as compared to the other zones in the ocean.The availability of warm temperatures, sunlight, and exchange of gases with the atmosphere makes it possible for may organisms to thrive in this layer and hence, the greatest biodiversity is supported by this zone in the ocean.

It's cell theory. easy name i would think.