The subtidal zone is the area of the ocean that lies below the low tide mark and remains submerged even during low tide. This zone is typically rich in marine life, including various species of fish, seaweed, and invertebrates. It extends from the shoreline to the continental shelf, where the ocean floor begins to slope downwards. In the subtidal zone, sunlight penetrates to varying depths, allowing for photosynthesis in some areas. This zone is crucial for ecosystems, providing habitats for organisms like coral reefs and seagrasses. It also plays a significant role in nutrient cycling and supports commercial activities such as fishing and diving.