They aren't just annoying

Have you ever waited all week in anticipation of visiting a lake with your family, packed all the bags, filled the car with gas, lathered everyone in sunscreen and arrived at the waterway to see the plants have grown so densely on the surface it looked like your kid was about to cannonball into a field rather than the lake?

Or you'd taken off work and prepped the boat for a weekend on the water only to turn around and go home because aquatic plants made you fear for your expensive motor?

A single plant species can do a lot of damage - especially when a water plant is not native to a particular area.

Invasive species, whether plants or animals, can have a devastating effect on the Brazos River basin's natural resources and the state. They can cause economic and ecological damage and impact human health.

The Brazos River Authority's Environmental Services Department regularly monitors the reservoirs and streams of the Brazos River basin for the presence of invasive species. This is one of the many ways the BRA tracks the health of the Brazos River basin ecosystem. The BRA, along with state and federal partners, work together to identify changes and make improvements that can aid the continued health and quality of the basin's water supply.

So, what are these giant, creeping monsters? The most common invasive plants in Texas are Kudzu, giant salvinia, water hyacinth, hydrilla, alligatorweed, Chinese Tallow Tree, and salt cedar.

What makes an invasive species so bad?

When non-native species are introduced to a particular area, they have few natural predators, competitors, or diseases to regulate their populations. This means that these non-native plants can take over ecosystems, spread rapidly, and decrease the biodiversity of native plants and animals. And unfortunately, prevention, detection, monitoring and repairing the damage caused by invasive species is extremely expensive. According to the Texas Parks and Wildlife Department, the nationwide annual economic impact of invasive species on the state exceeds $120 billion. Invasive aquatic species impact fishing and hunting opportunities, property values, water recreation, and water quality.

It's not so much like a burglar in the night, dressed in blank and wearing a ski mask is creeping across the banks of the Brazos and planting invasives in hopes of ruining your next fishing expedition. There are various ways invasives make their way to locations where they don't belong, such as when boaters don't clean, drain and dry their watercraft.

Giant Salvinia, a highly invasive aquatic fern and water hyacinth, a non-rooted flowering aquatic plant, love to hitch rides on boats, trailers and gear, and travel from lake-to-lake costing Texas taxpayers millions of dollars.

Kudzu, on the other hand, is believed to have been introduced to the Lone Star State to help stabilize erosion along riverbanks or as a decorative garden plant. According to texasinvasives.org, without natural controls such as pests that feed on the plant, this noxious weed crowds out plants that are native to Texas. The kudzu vine grows at an alarming rate of up to 1 foot a day, according to the Texas Invasive Species Institute.

Water hyacinth, introduced to Louisiana in the late 1800s, has spread across the Southern United States from Florida to Texas and has been reported as far west as California. From time to time, this species has been identified in the Brazos River basin in Lake Limestone, in Bessie’s Creek in Waller and Fort Bend Counties and in the Upper Oyster Creek watershed in Fort Bend County. Unlike native plants, its primary means of reproduction is through fragmentation, meaning pieces broken off of the parent plant can grow and establish new plants. So every time a boat propeller travels through a stand of water hyacinth or a landowner runs over it with a lawnmower at the shoreline, the number of plants can double, triple, or more depending on the number of fragments created.

Aquatic invasive species have been and will continue to be an issue that requires targeted control, prevention, and monitoring.

Over the past five years, the Texas Parks and Wildlife Department has treated more than 60,000 acres of giant salvinia, 6,000 acres of water hyacinth, and nearly 1,000 acres of other species of aquatic plants thanks to funding allocated for these efforts by the Texas Legislature, according to TPWD. Also, nearly 1.5 million giant salvinia weevils were introduced as biological controls and new projects to manage river and creekside invasive plants were implemented during that time.

"Nationwide, the annual economic impact of all invasive species in the U.S. has reached approximately $219 billion, with global impacts estimated at over $4 trillion," according to the TPWD in an April 2021 release. "Aquatic invasive species are among the worst of these, requiring considerable effort to prevent, monitor for, and effectively manage and mitigate infestations when possible. In response to this need, for the past five years — since the state’s fiscal year 2016 — the Texas Legislature has allocated approximately $3.2 million per year to combat aquatic invasive species in Texas."

"Our integrated pest management strategy for invasive aquatic plant management continues to improve, as we employ mechanical booms to contain plants for rapid response and to prevent spread, explore new herbicide treatment options, and continue the use of biological controls," said John Findeisen, TPWD aquatic habitat enhancement team lead in the release. "Through a combination of floating booms and several herbicides, giant salvinia was successfully eradicated from Lake Fork in 2019. However, common salvinia—another invasive aquatic plant — can still be found in the reservoir."

Since Texas' rivers and reservoirs are used for both recreation and drinking water, management of aquatic vegetation is regulated under the State Aquatic Vegetation Plan.

When aquatic nuisance vegetation appears in a private lake or pond, control is up to the landowner, though certain control methods are governed by state law. Treatment proposals must be submitted for review to the TPWD before vegetation management activities are conducted in public water.

Nationwide alerts from the U.S. Geological Survey were triggered in March 2021 when reports of the invasive zebra mussels were found in an aquarium moss package in a pet store. The destructive shellfish was discovered in pet stores in at least 21 states, from Alaska to Florida. Moss balls are ornamental plants imported from Ukraine that are often added to aquariums.

"The issue is that somebody who purchased the moss ball and then disposed of them could end up introducing zebra mussels into an environment where they weren't present before," said USGS fisheries biologist Wesley Daniel in a release. "We’ve been working with many agencies on boat inspections and gear inspections, but this was not a pathway we’d been aware of until now.”

In addition to zebra mussels, the most common invasive animals in Texas and the Brazos River basin are feral hogs and nutria.

Also remember, just because you’re done with a fish tank, doesn’t mean its contents should be flushed or dumped in a nearby waterway. Many non-native fish have been introduced into state waterways through the dumping of fish tanks. Around 2007, during a fish kill in Upper Oyster Creek in Fort Bend County, over half of the identified fish were non-native aquarium fish.

You don’t have to be a landowner to help prevent the spread of invasives, though. Reporting sightings help when individuals take a picture of the plant, records the GPS location, and sends it to Texas Invasives. These can be in trees, gardens, vacant lots, roadsides, yards, agricultural areas, wetlands, ponds, and lakes. Early detection is crucial to stopping the spread of invasive species.

You can stop aquatic hitchhikers by remembering the phrase, “Clean, Drain and Dry” every time you leave a body of water. Per Texas Invasives, you should:

• Inspect your boat, trailer and gear and remove all plants, animals and foreign objects from hulls, propellers, intakes, trailers, and gear before leaving a launch area.
• Drain all water from your boat, including the motor, bilge, livewells and bait buckets before leaving a lake.
• Wash your boat, trailer and other equipment before traveling to a new waterway.
• If you are leaving a water body that is known to have zebra mussels, leave your boat and trailer out of the water for at least a week or wash it at a commercial car wash using high-pressure, hot (140 degrees F) soapy water to kill microscopic zebra mussel larvae that may be hitching a ride.
• Never transport water, animals, or plants from one waterbody to another -- either intentionally or accidentally! Do not release live fish, including bait, into a new body of water.
• Whether you have obtained bait at a store or from another body of water, do not release unused bait into the waters you are fishing.

Every Texan should care about helping reduce or stop the spread of invasives; otherwise, these species will continue to require significant dollars to treat, control, and remedy damage caused.

Whether you’re a hiker, biker, camper, bird watcher, gardener, fisherman, boater, hunter, logger, forester, rancher or farmer, invasive species can have a negative impact on you.

Learn more about invasive plants and animals here.