Estuary Salinity Gradient Diagram | Freshwater to Ocean Transition #171515 (License: Personal Use)

This educational diagram depicts the transition from freshwater (0 ppt) at the river mouth through intermediate and brackish zones to fully saline ocean water (>15 ppt). It shows submerged vegetation thriving in the brackish zone and labels key features including the river, ocean, and salinity range. The gradient arrow emphasizes increasing salinity downstream.

Used in environmental science, marine biology, or geography educational content to explain estuarine ecosystems; matches user intent for learning about coastal hydrology, habitat zonation, or ecosystem dynamics.