Why are deep oceans and dark areas have no green plants?

Deep oceans and dark areas lack green plants primarily due to insufficient sunlight for photosynthesis. Most green plants and phytoplankton, which are the primary producers in marine ecosystems, rely on sunlight to convert carbon dioxide and water into energy. In deep waters, light penetration is minimal, preventing the growth of these photosynthetic organisms. Additionally, the nutrient availability in these regions can be limited, further inhibiting plant growth.