What is abyssal zone in a marine ecosystem ?

Explanation

### Step-by-Step Solution:

1. **Definition of Abyssal Zone**: The abyssal zone is a specific region in the marine ecosystem that exists at depths greater than 2000 meters underwater.

2. **Characteristics of the Abyssal Zone**:
- **Depth**: It is found below 2000 meters, making it one of the deepest parts of the ocean.
- **Light Penetration**: This zone is characterized by complete darkness. No sunlight penetrates to this depth, which means there is no photosynthesis occurring in this region.

...