As a result, riverine discharges of freshwater and nutrients are responsive to changes in rainfall in the drainage basins, and riverine discharge of nutrients is responsive to anthropogenic activities in the drainage basin.
Buoyant plumes are quickly responsive to wind.
In the U.S., the Mississippi River is the major large river , with discharge equal to approximately 2.2 x that of the Columbia River and 2.9 x that of the Yukon River. The Mississippi River supports much of the biological production in the northern Gulf of Mexico. There is a direct relationship between the flux of inorganic nitrogen into the northern Gulf of Mexico via the Mississippi River and the primary production observed within a 6900 km area around the delta. High rates of primary production stimulate and support high rates of zooplankton production. There is a characteristic group of copepod species in the vicinity of the Mississippi River plume which is numerically dominated by Temora turbinata , Eucalanus pileatus , Centropages furcatus , Paracalanus spp.