Inflows develop estuaries by diluting seawater and creating a series of salinity gradients that are the perfect mix for supporting coastal creatures. The further distance the freshwater flows toward the sea, the more diluted the saltwater becomes even further from the river s mouth. Inflow and turbidly determine the rate of sediment distribution which help in the fertilization and food growth within an estuary system. Over time, sediments are spread over river deltas and marshes helping to feed and fertilize the underwater habitats. The sediments are extremely important in maintaining life in deltas and marshes.
Sediments prevent subsidization, drowning and even disappearance of deltas and marshes.
Freshwater inflow is on a downward trend both in Texas and the United States due to the rising rates of population and their dependency upon the land and water systems. A prime example of the loss of freshwater inflow to estuaries would be in the state of Florida. Shrimp and lobster grounds are diminishing rapidly as well as sponge beds that have died. Large alga plumes are spreading for miles. Ninety percent of freshwater flowing from Lake Okeechobee into estuaries and bays is being diverted into drainage canals for major cities.