A "tributary".
Majority of rivers and streams have fresh water flowing in them.
The Baltic receives fresh water from more rivers and can be called brackish, only slightly salty
Rivers : flowing fresh water. Wetlands : tidal flows or almost none, brackish water (i.e, partially salt).
Because of the number or rivers flowing into the Baltic providing a vast quantity of fresh water
Essentially there are two main types, Static Water(called lentic) and Flowing Water (called lotic).
Generally, these are rivers called estuaries.
A mix of fresh and salt water is called brackish water. It usually occurs in estuaries where rivers meet the sea.
Fresh water can be found in various locations on Earth, including rivers, lakes, and groundwater reservoirs such as aquifers. Rivers are bodies of flowing fresh water that typically originate from springs or melting snow. Lakes are large bodies of standing fresh water that can be natural or man-made. Groundwater reservoirs, such as aquifers, are underground layers of permeable rock or sediment that store and transmit fresh water.
It is a fresh water stream.
Rivers are important to healthy beaches because the rivers empty into the beach and the rivers water is always fresh, thus making a fresh healthy beach.
Fresh water mainly comes from precipitation, such as rain and snowfall. Other sources include underground reservoirs called aquifers, rivers, lakes, and glaciers. The water cycle plays a vital role in replenishing freshwater sources naturally.
When fresh water meets seawater, it is called a "brackish water" environment. This occurs in estuaries or coastal wetlands where rivers flow into the ocean.