Most ocean life is found in coastal habitats on the continental shelf.
Why Coastal Habitats?
Despite only occupying about 7% of the total ocean area, coastal habitats on the continental shelf teem with life. This is due to a variety of factors:
- Sunlight: Coastal waters are generally shallower, allowing sunlight to penetrate more easily. This fuels photosynthesis by phytoplankton, the base of the marine food web.
- Nutrients: Rivers and land runoff carry vital nutrients to coastal areas, promoting the growth of marine organisms.
- Habitat Diversity: Coastal areas offer a wide range of habitats, from rocky shores and sandy beaches to estuaries and coral reefs. These diverse environments support a vast array of species.
- Upwelling: In some coastal regions, upwelling currents bring nutrient-rich water from the deep ocean to the surface, further boosting productivity.
Comparison with the Open Ocean
While the open ocean is vast, its productivity is generally lower than that of coastal areas. The deep ocean, beyond the edge of the continental shelf, lacks sunlight and receives less nutrient input.
| Feature | Coastal Habitats (Continental Shelf) | Open Ocean (Deep Ocean) |
|---|---|---|
| Sunlight | Abundant | Limited/Absent |
| Nutrients | High | Low |
| Habitat Diversity | High | Lower |
| Productivity | High | Low |
| Life Abundance | High | Lower |
Therefore, while marine life exists throughout the ocean, the highest concentrations are undeniably found in the vibrant and productive coastal regions on the continental shelf.
