Andi Fitzgibbon, a biologist with the U.S. Army Corps of Engineers Pittsburgh District’s Water Quality team, records field data from water samples to determine the water quality’s “sonde,” which measures temperature and related parameters such as dissolved oxygen chlorophyll turbidity near Warren, Pennsylvania on March 30, 2023. The district’s Water Quality team collected water samples from the Allegheny River both before and after the spring pulse to compare the pulse’s effect along various points on the river. The collected samples are sent to the Corps of Engineers Research and Development Center to test and analyze myriad factors such as pH acidity, alkalinity, metals, nutrients, and conductivity. (U.S. Army Corps of Engineers Pittsburgh District photo by Andrew Byrne)