TEXAS GEMS -Mustang Island State Park

Site Description

Large site that protects a significant example of the entire barrier island ecosystem from beach zone through dunes, prairies, marshes, hypersaline coves and open bay front. No other site on Mustang Island comes close to preserving this entire system, and the remainder of the island is increasingly fragmented and developed. The site preserves critical habitat for the endangered piping plover, as well as a home for hundreds of species of birds and wildlife, including amphibians, reptiles, birds and mammals, which are being extirpated elsewhere on the island and adjacent mainland.

Date Established:

1974

Date Information Updated:

2003

Location:

Texas; Nueces County; lat. 27*41’, lon. 97*11’

Relative Size:

~4,060 acres

Area of Influence:

Site is ecologically influenced by adjacent bay and adjacent developed and undeveloped lands, most critical in an area adjecnt to the site of roughly 3000 acres.

Ecological and Cultural Characteristics

Habitat type:

Full range of barrier island habitats, including open gulf, surf zone, beach, foredune, dune, back dune, lagoon, freshwater marsh, strand prairie, mud/salt flat, tidal marsh, hyersaline cove, seagrass beds and open bay.

Rare/Endangered Species:

Portions of the site are designated critical habitat for the endangered piping plover. Brown pelican and reddish egret (stet listed) also use the site frequently. Less common visitors include peregrine falcon.

Breeding/Nursery Are:

Not known if there is a colonial waterbird nesting site in park, but brush near bay is used for solitary nesting sites. The marshes and coves are particularly important nursery areas for a wide variety of game and non-game fish and wildlife, especially crustaceans including crabs and shrimp. The interface of shallow open water, seagrass beds and emergent vegetation provides both food sources and cover for eggs, fry and fingerlings to develop.

Forage Area:

All of the habitats found in the park are important foraging habitats for migratory and resident wildlife. Migratory shorebirds, such as the piping plover, forage for invertebrates on beaches and mudflats. Other birds, including owls, kites and raptors, forage on the abundant insects and rodents in prairie and marsh. Terrestrial vertebrates, including reptiles, amphibians and mammals, both herbivores and predators, flourish on the site’s rich and diverse resources. Seagrass beds provide forage for migratory waterfowl. Aquatic invertebrates, such as mollusks and polycheates, form important food sources for many birds and fishes. The coves and marshes are important to virtually all species of commercially important fishes, including red drum, spotted seatrout and flounder.

Migratory Species:

See above. In addition to supporting many species of migratory waterfowl and shore/wading birds, site is on flyway for migratory neo-tropical songbirds, including warblers, hummingbirds, sparrows, buntings, orioles and so forth. The site is particularly important to grassland species, many of whom winter here, and migrate to northern states, Canada or the Arctic for the summer. Fish migration is complex, but the intensely productive foraging resources of the surf and especially the bay-side coves, attract a number of sub-tropical fishes near the northern limits of the their ranges, as well as Atlantic species near the southern limits of their ranges.

Geomorphic Features:

Site is a barrier island. Primary geomorphic features include beach, dune systems, lagoons and a mid-island “ridge” of uplands.
Ecosystem Function:

Full range of functions in addition to above. Minimum development of the site and limited prior disturbances result in a system which is today relatively healthy, mature, stable and historic. Specifically, the large undeveloped area of the site, the flat topography and low surface runoff rate, means that the site is useful for recharging local ground water strata and filtering sediment and pollutants from surface water. Lagoons and diverse indigenous vegetation communities preserve a diversity of terrestrial wildlife, including species, such as coyote, extirpated from much of the region. Many such species require not only large undisturbed areas, but a range of resources, including cover, fresh water, and a healthy food base, of insects, small mammals, reptiles and so forth. As development encroaches, the value of the site for preserving examples of these habitats and gene pools will only increase. The site should be enlarged, enhance and protected now to the extent practical for future generations. As a barrier island, the site is invaluable for mitigating wind, wave and storm surge action, protecting the mainland, especially valuable human development and land uses, from the full brunt of tropical storms and hurricanes.

Uniqueness of Natural Community:

The community of the barrier island is unique in that it is “trapped’ on the island, and the climate and environment are relatively “harsh”, resulting in a system that is very specifically adapted to the special conditions of the site. This includes hypersaline coves and marshes, mud and salt flats, and sandy dune systems so saline and well drained that they support desert-like communities found only here and hundreds of miles inland where rainfall levels are much lower. Heat, humidity, and at times, scarceness of available freshwater, means stressful conditions and favors species with many of the same adaptations as desert species. The lack of trees means that birds and other wildlife develop special tactics for avoiding predators. The combination of habitats, unique soils and hydrology, and local environment of the barrier island, result in a community not found on the mainland, or anywhere else for that matter.

Archeological and Cultural Significance:

Little is known about the prehistoric use of the island. Since the Texas coast was submerged to its present elevation at the end of the last period of glaciation, and the barrier island emerged since that time; only about five thousand years ago, the site, as such, could not have been occupied by Paleo-Americans. On the other hand, shells midden sites along the bay side of the island, indicate that native Americans have been visiting the island and exploiting the resources of the bay and gulf for several thousand years. There are no known to be a lot of archeological sites in the proposed project area, and those that are known have been systematically studied, so it is difficult to address their uniqueness, richness, or potential to contribute to the scientific body of knowledge about local prehistoric peoples. The island was not used extensively by Europeans Americans in the 19th c., due undoubtedly to the harsh climate, lack of access, and periodic hurricanes. The island was primarily used for grazing cattle, although there were a few homesteads and farmsteads over the years. No sites of special state or national significance occur in the project area.

Current and Potential Use of the Site

Educational Use:

Current emphasis of site is on controlled public access and non-consumptive outdoor recreation. Currently some public interpretive program, which is scheduled to increase markedly over the next 2 years. Potential for education is immense, with more than a million visitors to the site each year.

Recreational Use:

Wide range of outdoor recreational activities currently enjoyed by millions of visitors. General water activities and sports, including surfing, sailing, kayaking swimming, shell collecting, bathing, sunning, picnicking, along with fishing, nature and bird watching, photography and graphic arts, and so forth. Owner resists requests to increase access for activities that would expand impacts to resources, and limits consumptive or destructive activities such as off-road vehicular usage.

Commercial Use:

Aside from a few old producing hydrocarbon wells, there is no commercial use of the site.

Private Use:

The entire area in the proposed GEM is owned and managed by the State of Texas. Large areas adjacent to the park are currently operated as nature preserves and or very low density private recreational “weekend” properties.

Management Status

Land Ownership:

TPWD

Existing Designations:

General protections accompanying management policies and requirements for designated State Park lands. Mission statement to preserve natural and cultural resources for present and future generations.

Small portion of site is designated State Archeological Landmark.

Management Status:

Approximately 1% of site is developed for pubic access (office, restrooms, parking). Remaining 99% is managed as historically occurring habitat/ecosystem for support of indigenous plant communities and wildlife. Goal is to keep as many elements of historic landscape and ecosystem intact and healthy as feasible.

Existing Monitoring Activities:

State and state’s partners are actively seeking favorable land acquisition opportunities from willing adjacent landowners. Some funds and agreements have already been identified. Site and adjacent management area likely to increase over next few years.

Management Needs:

Site is currently relatively mature and healthy. Vegetation baseline data is available. Faunal surveys (i.e. reptiles; small mammals) would be helpful. Greatest needs are “operational”, i.e. public access, development and interpretive planning and implementation, intended to limit impacts as demand for services and visitation increases.

Site Viability

Threats to Ecological Integrity:

No urgent threats. Biggest threat is failure to manage growing visitation, but management policies of agency should control the threat. Other threats include oil/chemical contamination on shorelines from spills, which have historically occurred, but from which the habitat has recovered quickly. Over development adjacent to park boundaries threatens to reduce biological viability of site, especially for large vertebrates and species requiring large areas. Urban development can also lead to predation of wildlife via domestic pets, nutrient overloads through runoff of lawn fertilizers, and related impacts.

Management Potential:

This is one of those ecosystems, which, because of the harsh/extreme environment, is not as threatened by invasive species as many others. Fire and other disturbance regimes do not appear to be required, although salt water inundation during storms will continue as it has for millennia. Currently the best management strategy, and the one being most strongly pursued, is the acquisition of adjacent lands and/or the acquisition of development/surface rights and/or conservation easements in order to limit future development that would negatively impact the site’s natural resources.

Source of Information

The information contained in this nomination are based primarily on the collective institutional knowledge and understanding of the site of the applicants.