TPWD News Release — Aug. 8, 2008
During the 1980s the 21,000-acre reservoir just north of Houston was the scene of a bitter battle over how to control hydrilla, an exotic plant that invaded the lake to such an extent it hampered boating and recreational use of the lake.
Yet not everyone hated hydrilla. Hydrilla provided habitat for fish, and in the absence of native vegetation, anglers wanted to keep it.
Over the objections of anglers and Texas Parks and Wildlife Department (TPWD) Inland Fisheries biologists, 270,000 non-sterile grass carp were introduced into Lake Conroe in 1981 and 1982, with devastating results.
In just two years the fish gobbled up all the vegetation in the lake. The lake still had plenty of bass and catfish, but the bass became harder to catch.
Perhaps even worse, the incident left a lingering legacy of distrust and acrimony among anglers, property owners and businesses.
In 1996 hydrilla was again found in the lake. Although it was kept under control with spot treatments of herbicide for the next eight years, it began to expand with a vengeance in 2005, covering more than 2,000 acres by January 2008, and many people around the lake feared another storm was brewing.
But a funny thing happened on the way to the battleground: People learned to work together for the good of all. Leading that process were two TPWD employees: Dr. Earl Chilton, aquatic vegetation manager; and Mark Webb, the Inland Fisheries biologist in charge of managing the fishery.
“By about 1995 we basically had no vegetation in Lake Conroe,” Webb said. “At that point enough of the grass carp died out that we began to see the return of some of the hydrilla. But at the same time, we had a native vegetation restoration initiative that Lake Conroe was a part of, and we began planting native plants. So for the next several years, up to about 2004, we kept the hydrilla under control with herbicides while we allowed the native plants to prosper and expand. In 2004 we began the introduction of triploid [non-reproducing] grass carp as well as using herbicides as part of an integrated pest management approach to try to keep those exotic plants under control while still allowing the native vegetation to grow and expand.”
The reintroduction of grass carp was not without controversy. “Angler groups were concerned because of history,” Webb said. “In the past they saw all vegetation removed from Lake Conroe by the use of grass carp to remove hydrilla. But there are a lot of differences now. We did not have a native grass community established in Lake Conroe at the time those first grass carp went in, and there were a lot more grass carp and hydrilla. The state of the reservoir is different today. Over time it has become more enriched and more capable of growing plants and sustaining fish and wildlife populations. But as far as the anglers were concerned, they just knew what had happened historically, and they were afraid history was going to repeat itself.”
Texas Parks and Wildlife Department was determined not to let that happen. “The then Executive Director Bob Cook pledged the department’s help until the problem was solved,” said Chilton. “His support was vital to the project’s success.”
“We are trying to learn from history and do a much better job this time,” Webb pointed out. “This time we have been working with angler groups, with homeowner groups, with local businesses, with the San Jacinto River Authority and with all interested parties to develop a plan to control the exotic vegetation in Lake Conroe while we introduce native vegetation and try to make the ecosystem as healthy as we possibly can for fish, for wildlife, for the homeowners, for the users, for everybody.”
Integrated pest management (IPM) is at the heart of the new plan. IPM is the coordinated use of environmental information and pest control methods to minimize pest damage while causing the least possible hazard to people, property and the environment. The Lake Conroe plan was developed with help from the Lake Conroe Association, the Bentwater Property Owners Association, the Bass Anglers Sportsmen Society (B.A.S.S.), Texas Black Bass Unlimited, Texas Association of Bass Clubs, Sensible Management of Aquatic Resources Team, the Seven Coves Bass Club and local business owners, local government officials and homeowners.
“By bringing everybody to the table from day one—angler groups, conservation groups, homeowner groups, business people, the controlling authority, everyone that has an interest in Lake Conroe from whatever standpoint—and by working together, we’ve developed trust among the groups,” Webb said. “The homeowner groups see that we are going to do what we say we will do in terms of controlling hydrilla. At the same time, the anglers see we are serious about continuing to establish native vegetation and keeping the native vegetation in the reservoir. It’s a balancing act, and everybody is not happy every day, but we are getting there. It’s a huge difference from what we had before.”
Webb credits the willingness of all concerned to work together with the success of the project. “The majority of the folks are truly trying to understand, and they’re looking for the healthiest ecosystem possible for everyone and for the fish and the wildlife that inhabit Lake Conroe,” he said.
And more and more people are not just observing what’s going on. They are taking an active role. “Seven Coves Bass Club got a grant of about $40,000 from the B.A.S.S. Federation Nation, a national fishing organization, and they have built a native plant nursery on property supplied by the San Jacinto River Authority,” Webb said. “With the assistance and advice of TPWD, the San Jacinto River Authority and the U.S. Army Corps of Engineers Lewisville Aquatic Ecosystem Research Facility, they are growing native aquatic plants to go into Lake Conroe. They have opened that opportunity up to anyone who wants to participate, and they are getting help from Master Naturalists, from Master Gardener groups, from local citizens. More people all the time are getting excited about coming in and helping to grow ecologically appropriate native plants to provide the kind of habitat we need for fish and wildlife in Lake Conroe.”
TPWD and the San Jacinto River Authority each contributed $25,000 to increase production at the plant nursery of carp-resistant native plants. TPWD has also obtained $150,000 in federal funding to help fight giant salvinia and water hyacinth, two other exotic species that threaten the lake.
In today’s world of limited water resources, Mark Twain’s words ring more true than ever. Water is for fighting over. But no longer do the people around Lake Conroe battle for control of the water in their lake. They fight to make the lake the best it can be.
By June 2008 hydrilla covered only 2.5 acres of Lake Conroe. “Now the focus will shift to the protection and enhancement of native aquatic plants for the benefit of the reservoir’s ecology and fish populations,” said Craig Bonds, TPWD’s regional director of inland fisheries. “TPWD’s actions will be data-driven and science-based. TPWD is committed to a balanced ecosystem at Lake Conroe and will do what is necessary to make that happen.”