TEXAS FRESHWATER by Matt Williams – September 2019

TEXAS SALTWATER by Calixto Gonzales – September 2019
August 24, 2019
August 24, 2019

The Green Monsters

SUMMER IS WINDING DOWN, but it’s still business as usual for John Findeisen and his crew. In their line of work the job never ends.

Findeisen heads up the Texas Parks and Wildlife Department’s Aquatic Habitat Enhancement Team. Tiny in number, the staff is charged with the huge responsibility of helping to keep an army of aquatic monsters in check on hundreds of inland waters across the state.

The monsters in question are invasive plants with peculiar names— giant salvinia, common water hyacinth, common salvinia, yellow floating heart and crested floating heart, just to name a few.

Some are considered noxious weeds. Any of them can gobble up large areas of water in short order and cause serious problems on numerous fronts.

Once established, the plants can form canopies so dense that native species might struggle to grow. Boating traffic may be impeded and water intakes clogged. Ecosystems can be threatened.

With 254 counties to cover and only six men to do it, this tall task spreads the team pretty thin at times. Their three pickups gobble up about 11,000 miles of asphalt each month.

“It keeps us busy,” Findeisen said.

Invasive plants have become a daunting problem that demands year-round attention on Texas lakes. Dealing with them is a costly proposition, too.

The Texas Legislature approved $6.3 million in funding to TPWD to fight aquatic invasive plants and animals in 2016-17 and again in 2018-19. Findeisen’s team has had a $1.73 million budget each of those years.

The money is used for purchasing herbicides, spraying equipment, fuel, floating booms, and boats. It also pays outside spraying contractors hired to help out on large bodies of water with widespread infestations.

Findeisen also allocates funds for rearing  giant salvinia weevils. The tiny insects eat the plant and reproduce on the leaves. When the eggs hatch, the larvae burrow into the plant’s stem. This causes it to die.

“We spend every bit of the money we get,” he said.

While any of the aforementioned plants can spell trouble for a reservoir, perhaps the most dreaded of all is  giant salvinia. This aquatic fern is native to the Amazon River Basin in Brazil.

Researchers believe the plant was brought to the United States years ago in a tainted shipment of tropical plants or fish. It was introduced to Texas waters sometime in the mid-1990s, most likely when a water garden overflowed or somebody dumped a contaminated fish aquarium into a creek or stream.

Findeisen said it was first discovered in Texas in 1998 in a small pond near Houston. It was found in Toledo Bend later that same year. The plant has since shown up in more than two dozen other public reservoirs, mostly in eastern Texas.

According to Findeisen, 18 Texas lakes are currently infested with  giant salvinia. Among them are Brandy Branch, Caddo, Conroe, B.A. Steinhagen, Livingston, Martin Creek, Murvaul, Nacogdoches, Naconiche, Lake O’ the Pines, Palestine, Raven, Sam Rayburn, Sheldon, Striker, Texana, Timpson and Toledo Bend.

The plant has been discovered and subsequently eradicated in a handful of lakes over the years, including Wright Patman, Welsh, Gilmer, Falcon and, most recently, at Lake Athens and Lake Fork.

Findeisen says the chances of eradication are always best when a new infestation is discovered early enough to be contained by floating booms. Then, it can be sprayed with herbicide or picked up by hand or nets before the plant has the opportunity to spread.

Sadly, a successful eradication effort is no guarantee  giant salvinia won’t rear its craggy head again on the same water body a year or two down the road. That’s because this plant is highly mobile in nature, extremely hardy and can be easily transported from one lake to the next.

Left untreated under good growing conditions, coverage areas can spread rapidly and double in size within 7 to 10 days. The plant can grow just about anywhere, but flourishes in still backwaters that are well-protected and largely inaccessible to boat traffic. As a result, it can become well-established before anyone knows a thing about it.

Compounding the problem is the fact that the plant floats and is not rooted to the bottom. This means it goes wherever the wind takes it.

giant salvinia is sneaky, too. The plant is prone to cling to whatever it touches, including boat trailers, duck decoys, boat anchors and trolling motors.

Experts believe the most new infestations occur when a boat trailer is backed into an infested lake and plants stick to the bunks or other parts of the trailer. The plants can live on moist trailer bunks for days and float free the next time the trailer enters the water. All it takes is a single sprig to lead to a  giant salvinia infestation on a lake where previously there was none.

Texas scientists have learned a lot about salvinia over the years. Herbicides will kill it, but they believe Mother Nature may be its worst enemy.

Findeisen says flooding combined with high wind will often flush the vegetation out of remote backwaters and into the main lake where it is subject to significant wave action. Wave action beats the plants up and eventually they wash up on-shore and die.

Heavy floods combined with a cold winter the last two years were a blessing for Caddo Lake. Caddo is a 26,800-acre lake near Karnack that ranks among the state’s top natural wonders.

According to Findeisen, giant salvinia covered nearly 6,000 acres at Caddo in Fall 2017. In March 2019, the coverage area had been slashed to 362 acres.

Speaking of Caddo, a really cool and entertaining video highlighting the battle with giant salvinia is currently circulating among film festivals across the country. Fittingly called There’s Something in the Water, the eight-minute animated documentary was co-produced by Dallas-area restaurateur, Shannon Wynne.

This informative film chronicles the history of  giant Salvina’s presence on Caddo and warns of the threats it poses to the natural lake and other waters where it gains a foothold. You can view the free trailer at www.theressomethinginthewater.com.


Email Matt Williams at [email protected]



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