An introduction Invasive Species Irene Spradlin Biology 1312 University of Houston-Downtown

What are Invasive Species? Invasive species are defined as an organism (plant, animal, fungus, or bacterium) that is not native and has negative effects on our economy, our environment, or health. Invasive plants and animals are the second greatest threat to biodiversity after habitat loss. Invasive species have come to Texas and we are noticing them and their impact.

History of Invasive Species Over the past 10 years or so, Texas has seen a large quantity of non-native land and aquatic species settle into its lakes, plains, and forests. The impact on native wildlife and state industry has been harsh. Invasive Species have few natural predators, competitors, parasites or diseases Have high reproductive rates Are long-lived

Giant Salvinia Giant Salvinia is found in lakes and ponds, oxbows, ditches; slow flowing streams and rivers, backwater swamps, marshes and rice fields. The majority of the infestation is located in East Texas. Rapidly expanding populations can overgrow and replace native plants which create dense surface cover preventing light and atmospheric oxygen from entering the water. Decomposing material drops to the bottom, greatly consuming dissolved oxygen needed by fish and other aquatic life. Giant Salvinia clogs water intakes interfering with agricultural irrigation and electrical generation. Many infested farm ponds in Texas lie on creeks that drain tributaries heavily depended on for agricultural irrigation.

Feral Hogs There are about 2 million feral hogs in Texas. Their numbers are continuing to increase because of their high reproductive potential and the lack of natural predators. Feral hogs wreak property, livestock, crops and pastures. Feral hogs have cause approximately $51.7 million in economic damages in Texas.

Saltcedar Saltcedar quickly becomes a monoculture along lakes and waterways. A single plant has been reported to transpire over 200 gallons of water per day. In the early morning and evening moisture with high salt content is exuded from the foliage, causing the soil to become saline. Saltcedar can choke waterways and has even dried up entire lakes. Native riparian species have been displaced by saltcedar, which in then causes displacement of native birds and animals that generally do not feed on the leaves or eat the saltcedar seeds. Once established the plants can become so thick cattle will not graze the area

Carrizo Cane Can grow up to 20 feet tall It uses large amounts of water Will crowd out other plant species and affect wildlife. Cane drains necessary water from agricultural areas and destroys aquatic habitats. It grows to be so thick and tall that it becomes a life- threatening hazard to border patrol officers performing their duty.

Zebra Mussel Have caused alarming declines in fish, birds, and native mussel populations by feeding on phytoplankton, an essential food source for many aquatic species. Originally from the Black and Caspian Seas, these quick- breeding mollusks have recently invaded several Texas lakes, but most profoundly Lake Texaoma,. They are threatening to take over the Trinity River Basin. Zebra mussels have negatively impacted the industry because they have spread, they could do more than hurt props: they could clog vital water intakes for drinking water, power plants and manufacturing.

Nutria Nutria are a large, semi-aquatic exotic rodent It has created problems for coastal marsh and bald cypress swamps in Texas. Nutria population has grown in recent years due to the collapse of the fur trade industry (for which they were originally breed during the first half of the twentieth century). Nutria feed on planted seedlings and saplings, and have consequently stripped hundreds of thousands of acres of marshlands and floodplains along the Gulf Coast. Efforts to regenerate destroyed regions have been unsuccessful, as nutria have been witnessed to destroy replanted vegetation even further.

Red Fire Ants These currant-colored insects have taken over open fields in Texas and the coastal prairie in Texas. Have caused dramatic reductions in native ants and insects. They also have affect amphibians and small mammals, Birds, especially those that are ground-nesters such as the bobwhite quail because these ants are known for eating newly-hatched chicks, or destroying unhatched eggs. Insects, lizards, birds, mammals, or amphibians that disturb a red ant’s mound run the risk of being immediately attacked and even killed.

Africanized Bees Africanized bees moved north from Mexico into Texas in the late 1980s. Their sting is dangerous to humans, livestock, and wildlife, and they cause severe economic losses to the honey industry. They also threaten crops like almonds and melons that depend on honeybees for pollination.

Black Tiger Shrimp Commonly referred to as “giant tiger prawns” They have turned up in the Gulf Coast in recent months. They are aggressive giant shrimp that can reach up to a foot in length and one pound in weight Tiger prawns a competitive advantage over smaller native shrimp when it comes to aquatic food resources. They feed on shrimp and crab which can cause native shrimp depletion There is a possibility that they carry diseases that native shrimp may not have the immune system to fight

Impacts of Invasive Species Displace native species Reduce biodiversity Reduce food available for wildlife species. Some invasive species kill native specie Economic impacts: Invasive species are responsible for tremendous economic losses through loss in forest and agricultural productivity, spread of diseases that impact humans, among other impacts.

What the Nature Conservancy is Doing The Nature Conservancy is working to prevent and control the spread of invasive species by: Providing Science Based Solutions Managing Invasions and Restore Habitats Encouraging Better Business Practices Promoting Stronger Public Policies Preventing and containing the spread of invasive species is vital to our efforts to protect native plants and animals across our lands, seas and rivers. ***We can also do our part by identifying bad plants in our back yard and getting rid of them.

Works Cited 1."TexasInvasives.org - Home." Texas Invasives. N.p., n.d. Web. 05 Aug “ Invasive Species: Aquatic Species.” Invasive Species: Aquatic Species. N.p.,n.d.Web. 05 Aug. 2014