Giant Salvinia Blocking Lake Access for Duck Hunters
Biologists fight back against giant salvinia
Giant salvinia covers about half of North Toledo Bend Wildlife Management Area’s 500-acre wetland impoundment, blocking boat access for duck hunters and keeping migrating waterfowl from food and habitat. The problem would be worse without steady work to fight back the invasive floating fern.
According to WMA staff, hunting can literally depend on “which way the wind is blowing,” as floating mats of salvinia blow across the lake. “In recent weeks the wind has been blowing from the east causing the western part of the WMA to be solid salvinia, with other smaller patches throughout the impoundment ranging in size from 10-15 square feet to several acres, and most of the sloughs or creeks have had some extent of salvinia in them,” said Bob Baker, a Texas Parks and Wildlife Department wildlife biologist at North Toledo Bend.
“We try to keep it at bay using herbicide through a collaborative effort with our Inland Fisheries team,” Baker said. He said $50,000 in gamebird stamp funds—paid by hunters—complements efforts. “The hope is more duck habitat becomes available when salvinia is slower to grow in late fall and winter and begins to die and sink as a result of the herbicide work. Another issue is parts of Toledo Bend reservoir used by hunters to boat to the WMA may be packed with giant salvinia as well.” Giant salvinia affects hunters, lakeside landowners and many others too. The plant affects hunting access at other WMA sites.
Giant salvina causing problems at Caddo Lake WMA
“Giant salvinia is bad on Caddo Lake Wildlife Management Area this year and has been consistently bad for the last four years at least,” said Vanessa Neace, Caddo Lake WMA wildlife biologist. “The closer to the big open water you go, the less salvinia there is. This still allows for some good duck hunting here, but the salvinia is another significant reason duck hunting is not what it once was at Caddo Lake.”
Neace points to an April 2016 TPWD photo of a duck blind on Caddo Lake. “This picture was taken after the 50-year Caddo Lake flood of March 2016,” Neace said. “The blind is draped in dead salvinia that was present during that March flood and simply clung to the blind as the water receded.” EPA-approved herbicide combats the problem. “Here on Caddo Lake, as at North Toledo Bend, the Inland Fisheries Aquatic Vegetation Management Program hires contractors to treat our salvinia,” said Neace. “They use herbicide and they grow giant salvinia weevils. Fortunately for Caddo Lake, we also have the Caddo Bio-control Alliance and the Morley Hudson Weevil Greenhouse.”
Texas Legislature gives money to fight giant salvina
In 2015, the Texas Legislative appropriated $6.3 million to TPWD for 2016-2017 to manage aquatic invasive species. That’s an increase from $1.1 million in the previous two-year funding cycle. Most of the funding goes for management actions to control multiple aquatic invasive species. But thanks to the increase, TPWD has funded a giant salvinia awareness campaign. Contributions from Sabine River Authority and Brazos River Authority help support the campaign. The campaign reminds people to “Clean, Drain and Dry” before traveling from one water body to another. Get more information at www.texasinvasives.org. Photo and information courtesy TPWD
