Freshwater, brackish, and salt marshes are found throughout the Galveston Bay system, on and just inland of shorelines.  This transition zone between water and land is dominated by plants that can tolerate fluctuating, and sometimes extreme, conditions.  Marshes can filter excess nutrients and sediment from runoff before it enters the Bay, and protect shorelines against erosion.  Marshes also provide food and refuge for a variety of wildlife.

Low salt marshes, like those found along the bayside of Galveston Island, are dominated by smooth cordgrass.  They are greatly influenced by tides and are typically flooded and exposed once a day.  This requires plants and animals to tolerate high salinities and frequent inundation.  High salt marshes are on higher ground and experience especially high salinities.  Only very salt-tolerant plants such as saltwort, glasswort, sea ox-eye daisy, and sea lavender can survive here.

Brackish marshes occur on somewhat higher ground, where salinity is lower and inundation less frequent.  Marshhay, saltmarsh bulrush, and Gulf cordgrass are common species here.  These marshes can be found in places like the north side of East and West Bays.

Freshwater marshes occur inland or in the estuary where rainfall or river flow is great enough to prevent regular intrusion by salt water.  Common plants include rushes, sedges, cattails and common reed.   Examples of managed freshwater marshes can be found at the Armand Bayou Nature Center and the Anahuac and Brazoria national wildlife refuges.  Freshwater marshes improve water quality by removing sediments and nutrients from waters flowing into estuaries.

Submerged aquatic vegetation (SAV) is comprised of rooted vascular plants found in areas that are continually covered with very shallow water.  In the Galveston Bay estuary, the most common types are widgeongrass and shoalgrass.  For these grasses to take root and grow, the water must be clear and without strong disturbances like storm surges or motorboat propellers.  This plant community provides valuable nursery habitat for economically valuable fish and shellfish.  Only small remnants of this habitat continue to survive in the Galveston Bay system, primarily in Christmas Bay.

Oyster reefs form in areas that are intermittently or continuously submerged, with a hard bottom and currents of water sufficient to bring in food and clear away sediments and wastes.  Complex reef communities are built over time, as new oysters settle on old oyster shells, and other animals are attracted to the food and shelter that the reef provides.  Reefs can also act as wavebreaks to protect adjacent shorelines from erosion.  Oyster reefs are common in mid-Galveston Bay, West and East Bays, and along the Houston Ship Channel.

Beaches and sandbars have little if any vegetation because of extreme physical conditions.  Constant wave and/or wind action, high salinities and relative instability of the soil are too much for most plants.  Many of the small islands in the Bay, which serve as bird rookeries, are primarily beach and sand bar habitats.

Flats are areas of exposed mud or sand that are regularly inundated by tides.  Typically, they lack plants or are only sparsely vegetated, but mats of algae often form on mud and sand flats.  Plankton (microscopic plants and animals) and detritus (parts of dead plants and animals), which form the base of the food chain, collect on these areas when tides are high.  Small organisms such as clams, shrimp and worms live in the muddy ground and are an important food source for wading and shorebirds.  Mud and sand flats can be seen at Bolivar Flats and San Luis Pass.

Cypress swamps are forested wetlands in permanent or nearly permanent standing water and are dominated by bald cypress trees.  Swamps may have an understory of woody shrubs or non-woody plants if enough sunlight reaches the floor.  The largest cypress swamp on the Texas coast is in Chambers and Liberty counties along the Trinity River.

In contrast to swamps, riparian forests have a high water table or are intermittently flooded, but usually do not have permanent standing water.  The wooded areas along Clear Creek, the San Jacinto River and Armand Bayou are examples of riparian woodlands.  Common species are oaks, elm, and ash.  Upland woodlands, which occur at higher elevations, also provide valuable habitat within the Galveston Bay watershed.  Oak motts occur sporadically throughout the area, even on Galveston Island and Bolivar Peninsula.  Chambers County supports many stands of pine trees.

There are 3 main kinds of prairie surrounding the Bay: salt, wet and coastal.  Salt prairies, composed primarily of Gulf cordgrass, are found in the transitional zone between salt/brackish marshes and upland grasslands.  They are characterized by saline soils. Wet prairies are also transitional areas, but between freshwater marshes and uplands.  They support a mix of upland and wetland species. Coastal prairies are upland grasslands that historically were dominated by grasses such as little bluestem, and indiangrass, with many species of wildflowers such as sunflower, gayfeather, and black-eyed Susan.  Throughout the Galveston Bay area, an exotic species, the Chinese tallow tree, is rapidly converting large areas of former prairie to tallow woodlands, which has little habitat value.

Much of the land surrounding Galveston Bay is used for agriculture, especially in Chambers and Brazoria Counties.  Rice fields are important economically for the crops they produce, and ecologically for providing many of the functions of freshwater marshes in the Galveston Bay system.  Like wetlands, they filter excess nutrients and other substances from freshwater runoff passing through them, and also provide food for birds and other wildlife.  Similarly, well-managed range lands can retain many of the functions of marsh or prairie, providing good habitat for many wildlife species.

Open Bay waters range from fresh to saline, depending on the location in the estuary, and the amount of freshwater entering the system.  The waters of Galveston Bay support a variety of organisms, including plankton, finfish, and shellfish.  The sediments of the open Bay bottom support many small worms, mollusks, and crustaceans, which are food for fish and shellfish.

Habitats are more than just places where plants and animals live.  They are also essential for food production, public health, a thriving economy, protection of property, recreation, and education.

Within the Galveston Bay watershed, vegetated habitats — such as forests, prairies, and especially marshes — slow erosion and actually help to build new land.  Upland plants slow rainwater and runoff, which can carry away sediments, and also trap sediments with their roots.  Marshes slow erosion by acting as wave barriers along shorelines.  When water passes through the marsh, it slows down, and sediments suspended in the water are deposited.  The roots of the marsh plants then trap the sediments, which are held in place against wave action.  This process, known as accretion, is how marshes are built and maintained.

Uplands are also created through accretion when, during high tides, sediments are carried into the highest parts of the marsh.  Over time, these sediments build up until the elevation is higher than the tides can reach.  Upland plants are then able to colonize the area.  Oyster reefs are another habitat which protect shorelines by acting as wave barriers.  Additionally, when oysters filter water to feed, they remove not only food, but also sediments.  By removing sediments from the water, vegetated and reef habitats help keep Bay waters clear for plants, animals, and people.

Marshes, prairies and forests also reduce the frequency and severity of flooding.  Plants in upland habitats slow rainfall, giving it more time to sink into the ground.  Water that reaches wetlands is captured and released slowly, as if from a giant sponge.  As water filters through vegetated habitats, the pollutants and excess nutrients, which can act as pollutants, are removed.

The ability of wetlands to store and release water also helps to keep rivers flowing and pushes back intruding saltwater, thus maintaining the salinity balance in the estuary.  Salinity balance is important to the plants and animals living in the Bay system.  Oysters, which are an important commercial fishery in the Bay, are sensitive to changes in the salinity balance.

Healthy habitat is essential to preserving Galveston Bay’s valuable natural resources and maintaining economic growth.  Habitats such as wetlands and submerged aquatic vegetation act as nurseries for fish and shellfish, including many commercially and recreationally important species.  Shrimp, blue crabs, and many finfish depend on Bay habitats, and without wetlands, there would be no seafood.  Other products, such as chicken feed and pet food, are also made from fish which spend some part of their lives in a Bay wetland.  Oyster reefs are important not only for the oysters they produce, but also for the habitat they provide for fish.  Fishing, and the businesses associated with it, brings approximately one billion dollars to local economies each year.  Likewise, businesses related to recreational boating make large economic contributions to Bay area communities.  It is unlikely that this would be the case if healthy habitats and clean water disappeared.

The Galveston Bay system includes the third largest port in the United States.  Taking place along its shoreline are one half of all chemical production, and one third of all the oil refining in  the U.S.  These industries contribute a great deal to the economy and also rely on the Bay.

Healthy habitats provide us with pleasant places to live, enjoyable activities, and opportunities to learn about our world.  The rich history of the area illustrates that people have enjoyed visiting and living near Galveston Bay for centuries.  The watershed includes the fourth largest metropolitan area in the U.S., as well as a variety of unique coastal communities.  Popular activities which rely on Bay habitats include:  fishing, boating, camping, hunting, watersports, and bird watching.  Three-fourths of all North America’s bird species, including several that are endangered, use Galveston Bay habitat.  The Bay is also in the flyway for birds migrating from South America.  The variety of habitats in the Galveston Bay system are an excellent source of educational opportunities.  Students enjoy learning about biology, geography, and history in the Bay’s outdoor classrooms.  Additionally, Bay habitats are important to researchers who are trying to find ways to keep ecosystems, economies, and people healthy.  People also look to Galveston Bay for its aesthetic values and for the scenic backdrop it provides.

Losses of wetland habitats in the Galveston Bay system since the 1950’s total more than 30,000 acres. Subsidence (the sinking of the land) and erosion are the two major causes for these losses.  Other causes, according to the Galveston Bay Plan, include conversion to uplands by draining the wetlands for urban development or agriculture, and dredging and filling for navigation channels.

Withdrawal of groundwater for drinking and industrial purposes has caused subsidence all around the Bay area.  As the elevation of the land surface dropped, marshes drowned and disappeared.  Subsidence occurred quickly.  "Before 1990, you could walk three-quarters to one mile out into the marsh along a trail at Galveston Island State Park without any more trouble than getting your feet a little wet.  Now [in 1997] there isn’t a trail or a marsh in that part of the Park, but I guess you could wade out."  — Gordon Nunn, Galveston Island birder. The water depth increased too quickly for the marsh grasses to "migrate" inland.  With the vegetation gone, erosion increased the rate at which shorelines receded.

Now that water supply sources have changed from ground water to surface water, subsidence near the Bay has returned to background levels.  However, the effects are still with us as unvegetated shorelines erode.  "The site where my grandfather built his house in the mid-1800’s is now two or three hundred yards out into East Bay.  All the land and marshes between the old home site and the Bay are gone."  —Dr. Joe Whitehead, a fourth generation resident of Smith Point, in Chambers County.

Erosion can also lead to losses of cultural heritage.  During an educational tour of the Smith Point area, a participant found a partial human skeleton in a shell midden on an eroding shoreline that once was protected by a marsh.  This discovery allowed an archaeologist to study the remains before further erosion could destroy or damage them.  The bones and other artifacts found in the midden added to the understanding of Karankawa Indian culture.  There is no way to know how many artifacts from middens have been lost to erosion.

Marshes are not the only important habitats being lost in the Galveston Bay area.  Riparian forests and prairie habitats also are important to the estuary, and are disappearing. Only a few scattered remnants of native coastal prairie remain.  From the 1950s to 1989, an estimated 1,400 acres of willow thickets and riverbank habitat were lost.

At first glance, riparian forests appear to have increased by about 3,600 acres, but most of this change is due to invasion by an exotic species, the Chinese tallow tree.  "When I was in high school you could look out over the prairies and see the town.  Now it seems that every fencerow is just solid with Chinese tallow.   Every time an oak tree falls in a hardwood lot, it seems that the gap is filled immediately by tallow."  —Mr. George "Pudge" Willcox from Anahuac, in Chambers County.  The rapid spread of this foreign species is a threat to both uncultivated agricultural lands, and to native forest trees which are of great value both for their economic uses and as habitat for wildlife.

Restoration and conservation projects are not exclusively the domain of state or federal agencies.  Local governments, conservation organizations and individuals, concerned about loss of habitats, have designed and conducted successful restoration projects within the Galveston Bay system.

Every piece of habitat conserved or created is important to preserve the biological diversity, heritage and economic value of the Galveston Bay system.  As examples of successful restoration, four conservation projects, undertaken by local governments, nonprofit organizations, industry groups, state and federal agencies, and individuals, are presented here.

The French Limited Site, an industrial waste disposal area, located near Crosby, Texas was closed in 1973, and declared a Superfund site in 1981.  The French Limited Task Group (FLTG) was comprised of companies that once used the site to dispose of industrial wastes.  FLTG was responsible for cleaning up the site and restoring 21 to 25 acres of marsh that had been degraded or lost.

The FLTG selected the former Brownwood Subdivision in Baytown from among 28 candidates for marsh restoration.  This area had subsided several feet from the 1950’s to 1983 because of groundwater extraction.  The city of Baytown condemned the area shortly after Hurricane Alicia.  The city planned to build a nature park there, but funds were limited.  FLTG and the City of Baytown used this opportunity to work together to create the city’s nature park and to satisfy the judicial consent decree.

Before creation of new marsh could begin, the remaining driveways, foundations, streets and utilities in the old subdivision had to be removed.  Channels were then dug to allow for tidal exchange with the surrounding bay and to create valuable "edge" habitat.  The site was graded to elevations suitable for low and high salt marsh.  Islands were also included to support freshwater pools, wetlands, and live oak motts to attract a variety of wildlife, especially neotropical migrant birds.  Limited public access was planned to increase the educational value of the marsh.  Foot trails, informational signs, and boardwalk trails were placed to allow viewing of wildlife with minimal disturbance.

This cooperation allowed Baytown to obtain its nature park while FLTG fulfilled the requirements of the consent decree.  The project has been recognized nationally and internationally.

The Interagency Coordination Team (ICT) was set up by the U.S. Army Corps of Engineers to oversee the safe disposal of dredged material and other environmental issues related to the planned expansion of the Houston Ship Channel.  The Beneficial Uses Group, a subcommittee of the ICT, evaluated possible beneficial uses for the dredged material.  The plans for disposal had to be environmentally sound and economically acceptable, incorporating, where possible, other public benefits.  One such public benefit is creation of new marshes to benefit wildlife and the businesses that wildlife supports.

Using dredge material, a marsh was created on an eroded section of Atkinson Island.  It was designed to test several methods of marsh restoration to find the best and most cost-efficient one for Galveston Bay.  Information on several factors, such as settlement and consolidation of dredged materials, was gathered.  Physical characteristics of nearby functioning marshes were surveyed to guide excavation of tidal creeks and determine the appropriate water depths of the created marsh.  Various planting densities for marsh grasses were tested to determine the most productive and cost-effective method of planting.

The success of this project is evident in the continuing improvement of many marsh functions, such as the increased habitat use by many species.  The Christmas Bird Count for 1996 found 62 species of birds at or near the marsh, including waterfowl, wading birds, shorebirds and even sparrows.  Other animals, such as crustaceans and worms, are also present, providing food for still other species.  This project demonstrated practical, economical and effective methods of marsh creation while adding over 200 acres of habitat to the Galveston Bay system.

Armand Bayou is a prime example of the profound impact subsidence has had on area marshes.  In the 1950’s, Armand Bayou was lined with freshwater marshes.  Mud Lake covered only 100 acres at high tide.  After 9 feet of subsidence, 100% of the freshwater marshes were lost, and Mud Lake now covers about 300 acres at high tide.  The loss of marshes caused localized reductions in populations of wading birds, waterfowl, and fish.

The Clear Lake/ Clear Creek Marsh Restoration Task Force, composed of private corporations, government agencies, and nonprofit conservation organizations, was formed to identify and restore critical areas in the Clear Lake and Clear Creek watershed.  Armand Bayou Site #4 is worth mentioning because of its unique construction methods and level of success.

The design plan designated the use of material dredged from Armand Bayou to create 5.74 acres of new marsh and a small pond.  This was the first attempt in Texas to dredge specifically for marsh creation, not as a byproduct of channel construction.  The Galveston Bay Foundation took the lead in restoring the site.  Permits, equipment, volunteers and cordgrass seedlings all had to be gathered and organized.  Member agencies of the Task Force helped as needed during the project.  Funds for the project came primarily from private industry and government agencies.

A temporary earth berm and brush fence were built to increase sediment accretion and material retention, and also to protect the site from erosion until the marsh grasses were well established.  Almost 400 volunteers planted thousands of stems of cordgrass.  Soon, new growth filled in the gaps between planted grasses until the marsh was lush.  Many species of birds and other wildlife now use the marsh for forage and cover.  In time, and without severe disturbances, this marsh should regain nearly all functions of a natural marsh.  This site is a model of habitat creation for improving conditions for wildlife in the Galveston Bay system.

 Mr. Bob Moore is a resident of Galveston Island and a student of the values and functions of wetlands.  He noticed during an unusually low tide in winter 1995 that easily-accessible oyster beds around the island were disappearing and what once was marsh was now devoid of all but a few scattered stems of cordgrass.  Without a marsh to support the food chain, the many fish prized by sport fishermen were disappearing.

Mr. Moore developed a plan that reclaimed valuable habitat and simultaneously protected his bayfront property from shoreline erosion.  A berm to act as an attachment site for oysters was built just offshore by stacking pieces of concrete riprap in a line, and mixing in oyster shells.  Ready-mixed concrete was poured over the berm to hold the shell and riprap in place.  Once the berm was completed, a bed for the new salt marsh was created using tested and approved dredged sand.  Mr. Moore and several volunteers then planted smooth cordgrass, obtained from Houston Lighting and Power Co., Inc.

To further protect the shoreline against erosion, a hard structure was constructed on the landward side of the marsh.  An attractive wall was designed, using bags of Sacrete stacked on top of each other like bricks.  Surprisingly, and thanks to all the assistance Mr. Moore received, this work was completed in only four days!

The new marsh has become a thriving ecosystem.  Marsh plants are doing well, and are providing both food and cover for many species of animals.  Rock crabs and blue crabs are found regularly.  White ibis and clapper rails forage on sand crabs inhabiting the new marsh and provide enjoyment for avid and not-so-avid birdwatchers.  Certainly, this habitat is not exactly the same as early naturalists encountered, but it is an excellent example of what can be done to balance the need for habitat and wildlife with human interests.  They need not be exclusive.

Some issues that affect Galveston Bay, such as subsidence and wastewater discharges, have had the attention of the public and government agencies for many years now, and solutions are being implemented.  More recently, new issues have emerged and been recognized as having an impact on the quantity and quality of habitat in Galveston Bay.  Two of these issues are the planning of flood control projects, and the control of nonpoint sources of pollution.  Their potential effects on habitat increase as the population of the Bay area continues to grow.  Awareness of these issues is important since the decisions we make today will affect Galveston Bay habitats, and the wildlife, people, and economy which rely on them, for generations to come.

Nonpoint source pollution enters a body of water but can not be easily traced back to a single source or point.  It is pollution that comes from the everyday activities of people who live, work, and play in the watershed.  Soils from erosion, or trash from a street, are solid forms of nonpoint pollution that are easily seen after a storm.  There are also many dissolved pollutants unseen in runoff.  Dissolved pollutants can have a larger impact on bayous and estuaries than solid debris because they affect a larger area and contact nearly all organisms within aquatic ecosystems.  Oil and grease from cars and trucks that are washed off of city streets during a storm are one example.  Other examples are excess pesticides and fertilizers from lawns and agricultural fields.  When inputs of pollutants exceed the capacity of ecosystems to remove them, significant damage can occur.

While nonpoint source pollution can damage habitats, some habitats actually can help remove pollutants.  Wetland plants help to improve water quality by trapping excess sediments and nutrients, such as nitrogen and phosphorus, from  runoff.  Some pollutants cannot be removed by wetlands or other habitats.  Highly toxic substances, or those not degraded after being consumed by decomposer organisms, may poison plants and wildlife.  If wildlife is not killed outright by the pollutants, toxins may accumulate in their tissues, making the wildlife unsuitable for human uses or for animals that eat the contaminated wildlife.  If we are to preserve the heritage and economic base of our coastal communities, we need to maintain a healthy estuary by reducing nonpoint source pollution.

As property development continues around the Galveston Bay system, flood control becomes a more pressing issue.  When development occurs in floodplains and upper watersheds, the volume of water entering rivers and bayous increases.  This, in turn, increases the size of the floodplain and the amount of development affected by flooding.  We now are faced with an additional challenge:  How to prevent flooding of our streets and homes while preserving valuable wetland and upland habitats.

One form of flood control is to widen and deepen a river or bayou and remove bends along its course to carry water through a watershed quickly.  These channels are good at moving large volumes of water quickly, but they eliminate productive marshes and riparian forests.  Under some circumstances, it is possible to channelize specific segments of a bayou without destroying large amounts of habitat.   Examples include bypass channels or channelization of only one side of the stream to alleviate flooding while preserving habitats on the other side.

Stream "rectification" (creating a mostly straight channel from a natural stream) also can produce indirect and unintended harmful effects on estuaries and freshwater wetlands.  Channelization can alter the seasonal flow patterns in rivers by changing drainage patterns in riparian wetlands.  Wetlands hold water and release it slowly over time.  If these wetlands disappear, pulses of inflow increase while reserves of water are no longer available to supply rivers during dry seasons.  Changes in inflow change the salinity of an estuary, which can cause serious illness or death in estuarine organisms, and possible temporary loss of important fisheries.

We can use the ability of various habitats to slow the rate at which water enters rivers and bayous as a model for flood control.  A common way to imitate these functions is with detention areas to catch runoff from a specific area of a watershed.  A detention area can become a city park that includes waterfowl habitat, hiking trails, natural areas, and open fields for sporting activities.  Where city parks are impractical, detention areas can be used to create new freshwater wetlands and attract a diversity of wildlife.  With multiple-use designs, local governments can get more use from limited funds and available land, and reduce potential losses of property by limiting development within a floodplain.

A buyout option may be needed when detention and selective channelization together cannot provide enough flood control for an area.  Buyouts work best in combination with other methods of flood control, when relatively few properties are at risk, and when further development within the affected floodplain is restricted.  Detention, channelization, or buyout alone is limited in its ability to control flooding.  A combination of two or all three methods may offer a workable and affordable compromise among ecosystem functions, water quality, and flood control.