Texas Parks & Wildlife Magazine   


Why Bays Matter

Texas needs bays, and Texas bays need fresh water

By Larry McKinney

The wind on Redfish Bay was cold and gusty as we prepared to launch our kayaks on an early morning last October. We had to cross a shrimp-boat channel where the north wind was pitching a steady train of high swells across our path, but that was a minor impediment. Once across, we turned into one of the myriad of tidal channels connecting the mangrove maze, seagrass flats and lakes that border the southwestern margin of the bay.

The winds diminished rapidly and when the sun rose fully above the horizon, we were treated to a scene that Audubon should have painted. Hundreds of birds, from stubby pelicans to elegant blue herons, had sought refuge from the wind in the stunted mangroves. Only a few feet from the bows of our kayaks, the common birds of the Texas Coast flapped and waded and hopped in a riot of colors, ranging from the hot pink of roseate spoonbills to the dun of plovers.

We glided past one another along the winding channels in the silent truce of the windblown. The occasional boom of distant duck hunters chased thousands of redhead ducks low overhead, seeking safer waters. In the middle of one such darkening passage of ducks, I spotted the first redfish of the day, industriously working the shallow bottom, its fanlike, iridescent tail waving in the air. Several more tails popped up behind that one. What a choice - birds or fish.

The fish won and I cast my voodoo-child fly just to its left. Even with the wind, the water in the protected lake was fairly clear, so I could see the fish briefly hesitate. I never finished my first strip. The redfish hit, I set the hook and the shallow lake exploded into action as the fly line ripped upward in a curtain of water. The fish and most of his buddies headed for the far side of the bay.

What is remarkable about this experience is that it is not an uncommon one on the Texas Coast. Yet few Texans would recognize it as something within their grasp. It is possible because of our state's most valuable and under-appreciated natural resources: our estuaries. Flowing into some 2.6 million acres of coastal waters, Texas estuaries create diverse wetlands that support the production of 100 million pounds of seafood annually and sustain an internationally recognized birding Mecca.

From space, Texas estuaries appear as evenly spaced pearls strung along 360 miles of coastline. Each of the seven major estuaries, or bays, as we more commonly refer to them, is different from the next. Their names ring with Texas history. LaSalle's ship foundered in Matagorda Bay. We won our independence from Mexico at San Jacinto, on the margins of Galveston Bay. The pirate Jean Lafitte cruised the waters of San Antonio Bay, slipping out to sea through Cedar Bayou.

Few Texans recognize our bays and estuaries for much more than this, if they note them at all. Less than half of the population of the City of Houston and Harris County, which occupies much of the northern margins of Galveston Bay, has swum in, fished in or boated on the bay.

Perhaps that helps explain why bays and estuaries have failed to win a place in Texas mythology, which is full of cowboys, oil rigs and wide-open land. It's difficult to appreciate the natural wonder of our bays as you whiz by them on the highway. At 70 miles an hour, they appear as dull expanses of water broken by intermittent stretches of marsh and mudflat. To really see their remarkable nature, you have to get out into them, and few people seem willing to do so nowadays.

Another reason our bays go unrecognized is their resilient nature. We tend to take them for granted, even though they deserve as much protection as other noteworthy ecosystems. We fret about and raise money to save Central American rainforests, old-growth timber in the West and coral reefs everywhere, and all the while we ignore the plight of the treasure at our back door. We fill in the wetlands (about half of Texas coastal wetlands are gone) to provide housing for the fastest-growing areas in the state. We crisscross bay bottoms with channels, drastically altering hydrology to speed commerce and promote petroleum development. We depend upon these waters to treat our waste and assimilate our pollution, which results in the closure of more than 30 percent of their waters to shellfish harvest. Through all of this abuse, our bays and estuaries persevere, absorbing blow after blow, rebounding only to suffer new abuse and serve yet again.

The resiliency of our estuaries is their greatest strength and ultimately may be their greatest weakness. Despite all of the abuses, each year these coastal ecosystems generate $2 billion in economic benefits from recreational fishing alone. Commercial fisheries average another $266 million. Coastal destinations account for about 30 percent of travel in Texas, and that translates into $10 billion in economic benefits each year. All these benefits are based on healthy and productive estuaries.

The good news for Texans is that our estuaries are absorbing all that we throw at them and they seem to come back for more. That means we still have the time to take those actions necessary to preserve them for our children. The bad news swirling below the surface and out of sight is that no matter how resilient our estuarine systems are, they do have breaking points. The world abounds with examples of broken systems: the Aral Sea, the Colorado River (the western one emptying into the Gulf of California), the Mississippi River, the Everglades, the Nile and on and on. The reasons for their destruction, in hindsight, are obvious: poor planning, greed, ignorance and just plain bad luck.

We can see the breaking point for Texas bays rushing toward us in the form of people. Texas' population is predicted to nearly double in the next 50 years. We already have used half of our natural resources, such as wetlands and hardwood bottomlands, to get where we are now. We cannot continue on that course. Unless we take steps to protect our bays and estuaries now, we may lose them in a crisis in the next 10 or 15 years.

We do not have to await that crisis. We can act now and do so responsibly and reasonably, in a way that balances all needs - municipal, industrial, agricultural and environmental. For Texas estuaries, the key to the future is water - freshwater inflows to maintain their integrity.

Freshwater inflows are important to these ecosystems for the most fundamental of reasons. An estuary is that place on the coast where fresh water from rivers meets and mixes with seawater. Sabine Lake, Galveston Bay, Matagorda Bay, San Antonio Bay and Corpus Christi Bay are vast caldrons where freshwater inflows create salinity gradients that expand and contract with drought and flood. Along with fresh water, the rivers that empty into them bring nutrients and sediments that feed both fish and wildlife and the wetlands in which they live and grow. Shrimp, crabs, oysters, redfish and spotted seatrout, to name only a few, have evolved to take advantage of these dynamic ecosystems. Their life cycles are inexorably linked to the ebb and flow of water into these systems. Adapted to flood and drought, they require both to prosper. Freshwater inflows mean fish to catch and shrimp to eat. If estuaries are like factories, the resource that fuels them is fresh water.

We have not always recognized that fact in Texas. Often has been heard the cry: "A drop of water past my dam is a drop of water wasted." Our earliest water plans, in the 1950s, proposed a canal to run the length of the coast that would capture flow from 11 major rivers and divert it to South Texas to irrigate a million acres of agricultural lands. To its credit, the plan did recognize the need for freshwater inflows to estuaries, and allocated 2.5 million acre-feet to supplement them. The average annual inflow to Texas estuaries is approximately 24.5 million acre-feet.

Thus began the first battles in a protracted war that often has pitted one Texan against another. The arguments took on new intensity following the drought of the 1950s, when we realized that water was, or could be, a scarce commodity that we should use wisely. We began to build reservoirs to hold enough water to get us through the next drought. When Texans start a project, we do it big, and today we have 4,790 square miles of surface water, almost as much as Minnesota, the land of 10,000 lakes. The water now captured behind dams serves a real need, for sure, but it is water that no longer nurtures the estuaries.

The Texas Legislature has continued to struggle with water issues, including the needs of bays and estuaries, through many sessions. In 1985, the 69th legislature directed the Texas Water Development Board and the Texas Parks and Wildlife Department to undertake the studies necessary to develop freshwater inflow recommendations for all Texas estuaries. This has been a long and difficult process that created a groundbreaking application of science to resource management that has not happened anywhere else. The study of environmental inflows required thousands upon thousands of hours by dedicated scientists and technicians, millions of dollars and 15 years of effort to complete. Today that work represents the best science available, and we have it just in time.

Senate Bill 1 (SB-1), championed by the late lieutenant governor Bob Bullock, was a historic piece of water legislation adopted by the 75th legislature in 1997. Addressing nearly all aspects of water management in Texas, it put the state in position to address its growing water needs. SB-1 provided the tools with which to address our state's future water needs. Now all that is needed are the means to use those tools to assure that enough environmental water will be provided to our rivers, lakes and estuaries to keep them healthy and productive. The 78th legislature is contemplating the next logical step - the framework within which we apply the science and make use of the tools we have to balance the water needs of Texas.

This is both a complex and a simple problem. The complexity is that no two Texas estuaries are similar. Sabine Lake has an abundance of fresh water and Corpus Christi Bay has too little. More and more thirsty people hem in Galveston Bay, and they live downstream from even more thirsty people in Dallas and Fort Worth. Many people want to move water destined for Matagorda Bay and San Antonio Bay to just about everywhere else. The simplicity is that all it takes to keep our estuaries healthy is water, and not even all of the water they normally receive, but water nonetheless.

We know the problem. We know the solution. We have the science and the means to apply that science. In this we are better prepared by far than anyone who has faced this challenge before us. Mark Twain once said, "Just do the right thing; it will gratify some of the people and it will astound the rest." If we have the will to do so, Texans can astound the rest.

How Do We Know How Much Fresh Water Bays Need?

Rivers and streams are the arteries for our estuaries, constantly carrying the nutrients and sediments that estuaries need in order to thrive. The river delivers the sediment into the quiet waters of the delta marsh, where it settles to the bottom, providing footing for marsh plants and shelter for myriad worms, clams and other animals. Within the sediments are nutrients such as nitrogen and phosphorous that feed marsh plants as well as millions of microscopic floating plants called plankton. The marsh plants shelter juvenile fish, shrimp and crabs from predators. The microscopic plankton are eaten by oysters that build reefs, which provide more shelter for fish and crabs. Without enough fresh water, sediment and nutrients, the estuaries we know and the benefits they provide us would cease to exist.

Understanding the importance of ensuring that estuaries stay healthy, in 1985 the Texas Legislature directed Texas Parks and Wildlife Department (TPWD) and the Texas Water Development Board (TWDB) to calculate how much fresh water, sediment and nutrients our estuaries need to remain healthy. These freshwater inflow studies, guided by Section 11.147 of the Texas Water Code, define beneficial inflows as a "salinity, nutrient, and sediment loading regime adequate to maintain an ecologically sound environment in the receiving bay and estuary system that is necessary for the maintenance of productivity of economically important and ecologically characteristic sport or commercial fish and shellfish species and estuarine life upon which such fish and shellfish are dependent."

TPWD and TWDB developed a method, now nationally recognized, for determining beneficial freshwater inflow needs for estuaries. During the last 15 years, scientists have collected information about the river flows, water circulation patterns, tides, weather, concentrations of salts, nutrients and sediment, and the fish and shellfish populations for seven major Texas estuaries. This information was analyzed in computer models to estimate how much fresh water each estuary needs and what seasons are important for freshwater inflow. Two computer models were created. A computer optimization model produced a freshwater inflow schedule that met state management objectives while producing optimal levels of finfish and shellfish. A second model predicted circulation patterns and salinity gradients that will result from the freshwater inflow patterns. To make sure the predictions of the computer models were reasonable, they were compared to TPWD data on fisheries and salinity for the past 25 years.

The computer model predictions are complete for all seven major Texas estuaries: Sabine Lake, Galveston Bay, Matagorda Bay, San Antonio Bay, Aransas Bay, Nueces Bay and Laguna Madre. Results show that all estuaries need high freshwater inflows during the late spring and early summer. Some estuaries benefit from having elevated freshwater inflows during September and October as well. Freshwater inflow requirements tend to duplicate rainfall patterns. Estuaries in East Texas are adapted to much higher amounts of freshwater inflow than estuaries in South Texas. Since East Texas experiences more rainfall than South Texas, on average, estuaries in the eastern part of the state receive more inflow in the form of runoff as well as freshwater inflows from rivers and streams. Rainfall patterns, which influence river flows, also dictate how much water is available for human uses.

Anyone who takes water from rivers or streams must obtain permission from the Texas Commission on Environmental Quality (TCEQ). The TCEQ must consider the effect on freshwater inflow to estuaries when it issues a permit to take surface water. TCEQ is required to include permit conditions "to the extent practicable when considering all public interests" necessary to maintain beneficial inflows. The freshwater inflow studies conducted by the TPWD and TWDB provide a scientific basis for the TCEQ as it evaluates water rights permits and establishes permit conditions.

- Cindy Loeffler

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