Is salinity low at mouth of river?

Salinity in the mouth of a river - an estuary - varies according to one's location in the estuary, the daily tides, and the volume of fresh water flowing into the estuary. read more

Salinity in the mouth of a river - an estuary - varies according to one's location in the estuary, the daily tides, and the volume of fresh water flowing into the estuary. Salinity is usually measured in parts per thousand (ppt) and the salinity of seawater in the open ocean is fairly constant at about 35 ppt. read more

In estuaries, salinity levels are generally highest near the mouth of a river where the ocean water enters, and lowest upstream where freshwater flows in. Actual salinities vary throughout the tidal cycle, however. read more

Most of the time the Severn's salinity is the same from Annapolis to well above Round Bay, and this is close to the salinity of the Chesapeake at the Bay Bridge. The Severn is about three-fourths of the way up the Chesapeake from the Atlantic to the mouth of the Susquehanna, which is the source of most of the water in the Severn. read more