Water Quality and Toxic Algal Presence in Burrow Pits in Eastern Lake Pontchartrain: 2021-2023

This dataset consists of sensor profile and water sample results from monitoring campaign to investigate the effects of two dredged pits in eastern Lake Pontchartrain on dissolved oxygen conditions within the water column in and surrounding the pits over a three-year period. The borrow pits were excavated to provide soil material to nourish three nearby protected marsh sites: Bayou Sauvage National Wildlife Refuge, Turtle Bayou Protected-Side Intermediate Marsh, and New Zydeco Ridge. The southern borrow pit occupies 418 acres and was monitored using a 9-point grid. The northern pit is 330 acres and was monitored using a 12-point grid. During 2021-2023, the U.S. Geological Survey, Lower Mississippi-Gulf Water Science Center, in cooperation with the U.S. Army Corp of Engineers New Orleans District collected data in the lake. Pit areas were sampled monthly in March, April, September, October, and November and twice a month during May, June, July, and August when possible.
A multi-parameter water quality sonde was used to measure dissolved oxygen concentration, pH, specific conductance, and salinity to monitor for the formation of hypoxic conditions. At each grid location, a 3-point vertical profile was measured. When hypoxic conditions were encountered (dissolved oxygen