Places We Protect

Laguna Madre


Bahia Grande coastal land.
Thomas tract Bahia Grande coastal land. © Dero Sanford

Texas and Mexico are bordered by the world's largest barrier island system.




The Laguna Madre, which spans the Texas’ lower Gulf of Mexico coastline and Mexico’s Tamaulipan shore, is a paradox—unassuming in appearance, the ‘Mother Lagoon’ is one of just six hypersaline coastal lagoons in the world. Stretching for hundreds of miles along the coast of five different South Texas counties and one state in Mexico, this region is a rich and biologically diverse ecosystem.

Its network of coastal wetlands, native grasslands, marshes, shallow bays, wind tidal flats and barrier islands provide critical habitat for an array of migratory and wintering shorebirds, including reddish egrets, brown pelicans, peregrine falcons, piping plovers and 90 percent of all wintering redhead ducks. Some of the most extensive colonial water bird rookeries in the state are located here. Federally endangered Kemp’s Ridley sea turtles, jaguarundi and ocelots also call the area home.

The shallow waters of the Laguna Madre account for almost 80 percent of all Texas’ seagrass beds and the region supports a variety of fish species, including spotted sea trout, redfish and flounder. Of the 44 species of fish identified in the Texas Gulf as commercial or recreational, 37 have been found in the Laguna Madre.

Reconnecting an Ecosystem

Myriad challenges threaten this unique coastal ecosystem, including ongoing development of the barrier islands, sea level rise, stormwater and agricultural run-off, and dredging. Human activity has created issues, too. A rising number of visitors to regional beaches and flats has reduced the amount of available area for wildlife to successfully nest and feed, free from human disturbances. To benefit tourists, large portions of the beach are also swept clear of seaweed, which is essential to the stability and health of sand dunes and the ecology of the sandy, Gulf Coast beaches.

Increased recreational and commercial boat traffic has also taken a toll, particularly on colonial nesting islands and the lagoon’s dense, shallow stands of seagrass beds.

Boats with outboard propellers are responsible for prop scarring, which happens when a boat’s propeller repeatedly slices into the shallow bay floor, uprooting the seagrass and permanently damaging the beds. Keeping those beds healthy and intact is critical to the Gulf of Mexico—seagrass helps filter pollutants from the water and provides critical nursery habitat for a variety of fish and shellfish. Science has shown that restoring prop scarred seagrass beds to full health is often unsuccessful, so The Nature Conservancy worked with partners to develop a pilot project aimed at protecting seagrass beds throughout the Upper Laguna Madre.  

In 2005 we began mapping previously-dredged oil and gas channels that crisscross the lagoon. We installed a series of navigational markers to delineate deeper waters—areas where boaters can run their watercraft without damaging seagrass beds. Since the launch of this program, we’ve erected channel markers throughout 18.5 miles of the Upper Laguna Madre, benefiting 8,965 acres of seagrass.

We’ve also partnered with state, federal and international agencies to reconnect and protect the coastal wetlands of the Mother Lagoon. In 1998, we collaborated with Mexico-based Pronatura Noreste to establish the Flora and Fauna Protected Area—Laguna Madre & Rio Bravo Delta, a 1.4 million-acre expanse of the Laguna Madre in Tamaulipas, Mexico. Mexico’s National Council of Natural Protected Areas currently governs the area.

Between 2000 and 2007, the Conservancy protected another 25,000 acres of the Laguna Madre in the United States, on the upper end of South Padre Island. Shortly after, we conveyed the island parcel to U.S. Fish and Wildlife Service to establish the South Padre Island Unit within the Laguna Atascosa National Wildlife Refuge.

 Cross-border Collaboration

We’ve also worked with USFWS to safeguard more than 2,100 acres within the region’s Bahia Grande coastal corridor. It’s the first land protection deal in Texas funded by the 2012 RESTORE Act, which was created to foster ecological and economic restoration throughout the Gulf of Mexico in the wake of the 2010 Deepwater Horizon oil spill.

The acreage stretches across the upper end of the Bahia Grande and features a mosaic of coastal wetlands, native prairies and brush. Preserving these tracts is critical to restoring Bahia Grande’s extensive tidal bay system and creating a 7,000-acre wildlife corridor that links the Laguna Madre to the Lower Rio Grande Valley. That passageway will benefit a range of wildlife, including the aplomado falcon and federally endangered ocelot. 

Like the acreage on South Padre, the newly-protected parcels within the Bahia Grande will eventually be incorporated into the Laguna Atascosa NWR, becoming another valuable link in a chain of protected lands on both sides of the U.S.-Mexico border. 



Laguna Madre


Laguna Madre

Map with marker: Laguna Madre

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