Sounds are typically brackish water, which is a mix of both freshwater and saltwater.
A sound is a protected body of shallow water situated between landmasses, often connecting larger bodies of water. According to the provided reference, a sound, such as the one between the mainland and the Outer Banks, is "fed by both inland tributaries and the ocean."
Why Sounds are Brackish
The unique location and water sources of sounds lead to their characteristic salinity.
- Freshwater Input: Inland tributaries (rivers and streams) carry freshwater into the sound.
- Saltwater Input: The sound is also connected to the ocean, allowing saltwater to enter.
Because of this combination of freshwater from land and saltwater from the ocean, the water within a sound becomes brackish, meaning its salinity is somewhere between that of pure freshwater and pure saltwater.
Understanding Brackish Water
Brackish water is not uniformly salty or fresh throughout the entire sound. Salinity can vary depending on factors such as:
- Proximity to the ocean inlet (usually saltier closer to the ocean)
- Amount of rainfall and freshwater runoff (can become fresher after heavy rain)
- Tides and currents
This dynamic environment supports a unique ecosystem adapted to fluctuating salinity levels.
