Dr. Nancy Rabalais checks the surface salinity with a refractometer before sampling water in the Mississippi River mouth. LSU students Abby Roche, Jill Tupitza, and Ben Farmer stand by for the go-ahead to collect their samples.

Dr. Nancy Rabalais checks the surface salinity with a refractometer before sampling water in the Mississippi River mouth. LSU students Abby Roche, Jill Tupitza, and Ben Farmer stand by for the go-ahead to collect their samples.