The suspended particles absorb sunlight required for plant photosynthesis and they give color to the water. The suspended sediments can eventually sink and become deposited on the Bay's sea floor.
Some toxic contaminants attach onto particles and are carried with the sediments by water currents.
The lower panel shows the changing distribution of suspended solids along the USGS Bay transect . The horizontal axis represents change over time, from 1993 through 1995. During periods of high Delta outflow, such as in early 1993, large quantities of suspended sediments are carried into the Bay from the Sacramento and San Joaquin Rivers. The water can become very turbid during these periods of rapid sediment input. During years of low Delta outflow, such as 1994, sediment inputs are reduced and the concentrations of suspended sediments are smaller.