PORT ISABEL, Texas (ValleyCentral) — Tens of thousands of redhead ducks are once again overwintering on the Bahia Grande Unit of Laguna Atascosa National Wildlife Refuge.

The 22,000-acre tract, with some 10,000 acres of wetlands, situated between Brownsville and Port Isabel, is undergoing a remarkable resurgence since the acquisition of the property by Fish and Wildlife in 2000 and subsequent re-inundation.

The vast tidewater basin sprawling across the southern tip of Texas, known collectively as Bahia Grande and now home to immense schools of redfish, represents the largest coastal restoration project in Texas and one of the largest in the United States.

For nearly a century, the historic wetland was dry. Construction of the ship channel connecting the Gulf of Mexico to Port of Brownsville in the early 1930s cut off tidal flow to Bahia Grande, desiccating a productive estuary and creating an immense dustbowl, where once thousands of waterfowl congregated and fish thrived.

A temporary pilot channel was constructed in 2005 reconnecting the estuary to Gulf waters, and last year the channel was deepened and widened creating a permanent channel increasing tidal circulation throughout the estuary.

Dr. David Hicks, Professor of Marine and Coastal Sciences at the University of Texas Rio Grande Valley, has been monitoring the restoration effort for some 20 years and is thrilled with the remarkable recovery.

“It is just amazing, since like 2012 when we first started seeing seagrass in Bahia Grande, that now it is covering hundreds of hectares.”

With the creation of the permanent channel and increased tidal circulation, salinity has been reduced prompting shoal grass to proliferate, which provides food and shelter for marine species and is the preferred food of migratory redhead ducks.

Now, after nearly a century’s absence, vast flocks of redhead ducks have returned to the historic Bahia Grande wetlands.