AUSTIN – At North Toledo Bend Wildlife Management Area, giant salvinia covers about half of the WMA’s 500-acre wetland impoundment, blocking boat access for duck hunters and keeping migrating waterfowl from food and habitat.

“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.

Another issue is parts of Toledo Bend reservoir used by hunters to boat to the WMA may be packed with giant salvinia as well.”

The hunting access problem is not limited to Toledo Bend. “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.”

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 Biocontrol Alliance and the Morley Hudson Weevil Greenhouse.”

Bio-controls will likely never completely replace management tools like herbicide, but the weevils are showing progress. Some key boat lanes are more open now because of herbicide treatment, and there is evidence of giant salvinia damage caused by weevils. But once a plant like this becomes established, eradication becomes almost impossible, and that makes steady management a necessity.

More information about how to identify and help control giant salvinia and other invasive species is at www.texasinvasives.org. Anyone can find more information about Texas public hunting and hunting at state wildlife management areas on the TPWD website.