Practical information to identify and manage non-native, invasive plants and animals
The Quiet Invasion:
A Guide to Invasive Species of the Galveston Bay Area
About Invasive Species
About Invasive Plants
Exotic plants are non-native species of trees, bushes, and flowering or non-flowering plants that are cultivated in regions outside of their native range. In other words, exotic plants grown in the Houston-Galveston region are not native to southeast Texas. Exotic plants may originally hail from other parts of the United States or even other areas of the world such as Asia and South America. Many species of exotic plants are popular with gardening enthusiasts because of their beauty, availability, low cost, and ease of cultivation.

Characteristics that make exotic plants popular with homeowners can also lead them to have negative impacts on native flora and fauna. Hardiness and an ability to reproduce and spread can lead some exotic plants to be characterized as invasive. When established in natural habitats, invasive plants can out-compete native plant species and decrease the amount of available habitat for wildlife that depend on native plants for nesting and feeding.

While not all exotics are invasive, some exotic plants are extremely aggressive and can escape from the areas in which they are originally planted. Rhizomes of invasive plants can spread under fences while seeds or plant fragments can be transplanted by the movement of people and equipment, wildlife, water, and wind. Invasive plants can spread to roadsides, vacant lots, agricultural fields, and native habitats such as coastal prairies, wetlands, and riparian forests along bayou banks. Once established in natural habitats, invasive plants can be very difficult and costly to control or eradicate.

About Invasive Animals
Exotic animals are insects, crustaceans, mollusks, fish, reptiles, birds, and mammals that exist in habitats outside of their native range. Invasive animals are those exotics that establish, reproduce and spread in the region to which they are introduced. Invasive animals cause negative ecological, social, and economic impacts. Invasives can be terrestrial or aquatic in nature and are introduced through accidental or intentional release.

Invasive species impact biodiversity, habitat quality, and ecosystem functions. They out-compete native species for food and habitat. They also introduce disease or may feed on native species. Additionally, invasives can decrease the amount of viable habitat available for native wildlife (e.g. by degrading water quality or destroying wetland plants). Invasive species can also impact human health and cause economic losses. Once invasive species are established, particularly in aquatic habitats, they are very difficult and often costly to control or eradicate.

Estuaries around the U.S. experience invasive species introductions. As a hub of human activity, the Houston-Galveston Region and Galveston Bay are no exception. This field guide discusses invasive animal species found in the Houston-Galveston region as well as invasive animals that could potentially invade the area.

The most cost effective way to control the spread of invasive animals is to prevent their introduction in the first place. Regulations are one tool used by state and federal agencies to limit invasive species introductions.

The Texas Parks and Wildlife Department (TPWD) maintains a list of prohibited exotic animal species for the State of Texas. Species of exotic animals prohibited by the agency cannot be imported, sold, or possessed by individuals without a permit. Violations can be reported to a local TPWD law enforcement office and are punishable as a Class C misdemeanor.

To stop the spread of invasive pests, the U.S. Department of Agriculture (USDA) establishes quarantine areas to restrict the movement of materials (soil, wood, and plant products) that may be infested by invasive species.

Many agencies and organizations act in a nonregulatory capacity to provide information to the public, help homeowners and land managers control invasive species, and restore habitats impacted by invasive species. Local examples of these organizations include the Armand Bayou Nature Center, Galveston Bay Estuary Program, Galveston Bay Foundation, Houston-Galveston Area Council, Texas Cooperative Extension Service, TPWD, US Fish and Wildlife Service, and others.
Page Updated/Reviewed: 08/31/2010 8:23 AM