The primary issue at Lake Conroe is the need to enhance littoral habitat including the native aquatic plant community while controlling invasive exotic aquatic vegetation. Lake Conroe has been in a state of flux since its impoundment in the late 1970’s with an early infestation of hydrilla followed by total removal of the aquatic plant community by 270,000 diploid grass carp stocked in the early 1980’s. Native vegetation restoration was begun in 1995 by Texas Parks and Wildlife (TPWD) and its partners, but increased nutrient loading caused by rampant urbanization along with attrition of the grass carp population led to a re-infestation of the reservoir by hydrilla and water hyacinth. In addition, the exotic aquatic fern, giant salvinia, was discovered in Lake Conroe in 2000. In 2006 TPWD, the San Jacinto River Authority (SJRA), the Lake Conroe Association (LCA), the Seven Coves Bass Club (SCBC), and other constituent groups created the Lake Conroe Habitat Management Plan for the control of exotic vegetation and the enhancement of the native aquatic plant community. Hydrilla, water hyacinth, and giant salvinia are now under control, but as a result of grass carp stockings as part of the integrated pest management (IPM) strategy, native vegetation was greatly reduced. In Phase 1 of the Lake Conroe Habitat Improvement Project (2005-2010) SCBC, SJRA, TPWD, and the US Army Corps of Engineers Lewisville Ecosystem Research Facility (LAERF) constructed a native aquatic plant nursery below the Lake Conroe Dam using grant funding provided by BASS; SCBC, SJRA, LAERF, and TPWD transferred approximately 2,500 mature plants from the nursery into Lake Conroe; and SJRA and LCA controlled approximately 2,000 acres of exotic vegetation including hydrilla, giant salvinia, and water hyacinth using a combination of herbicide, mechanical control, and grass carp introductions.
Size and Scope of the Lake Conroe Project:
The primary issue at Lake Conroe is the need to enhance littoral habitat including the native aquatic plant community while controlling invasive exotic aquatic vegetation. Lake Conroe has been in a state of flux since its impoundment in the late 1970’s with an early infestation of hydrilla followed by total removal of the aquatic plant community by 270,000 diploid grass carp stocked in the early 1980’s. Native vegetation restoration was begun in 1995 by Texas Parks and Wildlife (TPWD) and its partners, but increased nutrient loading caused by rampant urbanization along with attrition of the grass carp population led to a re-infestation of the reservoir by hydrilla and water hyacinth. In addition, the exotic aquatic fern, giant salvinia, was discovered in Lake Conroe in 2000. In 2006 TPWD, the San Jacinto River Authority (SJRA), the Lake Conroe Association (LCA), the Seven Coves Bass Club (SCBC), and other constituent groups created the Lake Conroe Habitat Management Plan for the control of exotic vegetation and the enhancement of the native aquatic plant community. Hydrilla, water hyacinth, and giant salvinia are now under control, but as a result of grass carp stockings as part of the integrated pest management (IPM) strategy, native vegetation was greatly reduced. In Phase 1 of the Lake Conroe Habitat Improvement Project (2005-2010) SCBC, SJRA, TPWD, and the US Army Corps of Engineers Lewisville Ecosystem Research Facility (LAERF) constructed a native aquatic plant nursery below the Lake Conroe Dam using grant funding provided by BASS; SCBC, SJRA, LAERF, and TPWD transferred approximately 2,500 mature plants from the nursery into Lake Conroe; and SJRA and LCA controlled approximately 2,000 acres of exotic vegetation including hydrilla, giant salvinia, and water hyacinth using a combination of herbicide, mechanical control, and grass carp introductions. During phase 2 of the project (2010-2012) 5 miles of the Lake Conroe shoreline were planted with native aquatic vegetation focusing on grass carp tolerant species to increase littoral fish and wildlife habitat, sequester excess nutrients, filter the water column, stabilize bottom sediments, control erosion, and fill empty niches to help control exotic aquatic plant species. Also during phase 2, four one-acre structural habitat areas (fishing hot spots) were created in the lower reservoir to increase fish production and angling success. Throughout the project educational efforts including magazine articles, outreach events, presentations, and a native vegetation restoration manual have continued to increase awareness of the need for controlling the spread of exotic aquatic plants and animals (including zebra mussels) and conserving the resources of Lake Conroe and the San Jacinto River Watershed. Cooperating media outlets serving the Houston Metropolitan Area where Lake Conroe is located include Houston Chronicle newspaper, Conroe Courier Newspaper, Dockline Magazine and numerous television and radio stations. Typically some aspect of the Lake Conroe Habitat Project is reported in these media outlets at least once a month. In addition, websites for SJRA, TPWD, USCOE LAERF, SCBC, BASS, TBBU and others contain project updates and information including videos and media links.
Benefits, Achievements, and Potential for Success:
The Habitat Enhancements for Fisheries and Ecosystem Improvement at Lake Conroe, Texas project is designed to provide self-sustaining and expanding habitat improvements that will continue to improve the Lake Conroe ecosystem for fish and other wildlife and human uses. The native vegetation component has and will continue to mitigate the increasing effects of urbanization (nutrient enrichment, sedimentation, etc.) in the watershed with little or no additional expenses to residents and other users. The exotic vegetation management plan associated with this project allows for the control harmful exotic aquatic vegetation at a greatly reduced cost compared to other management efforts due to the integrated approach using low levels of biological and chemical control along with sustained expansion of native vegetation to fill empty niches and provide resistance to re-invasion by exotic plants. The technology transfer from methods developed during this project will help conservation projects nationwide. The structural fisheries habitat developed during this project will allow recreation and education opportunities into the future. Direct measures of success include the number of native aquatic plants produced and transferred to the reservoir (over 3,000 to date), acres of native aquatic vegetation in the reservoir as a result of planting or reduction in competition with exotic vegetation (1,850 acres currently), and reduction in harmful exotic aquatic vegetation including hydrilla, giant salvinia, and water hyacinth (over 2,000 acres controlled to date).
The project has been a direct model for construction of native aquatic vegetation nurseries at the Texas Freshwater Fisheries Center in Athens, Texas, a cooperative native aquatic vegetation nursery at Baylor University, and native aquatic vegetation nurseries being constructed for use in conjunction with restoration projects at Lake Houston, Lake Raven, and Lake Livingston, Texas. The integrated pest management model and native vegetation restoration techniques developed through this project are being used at numerous reservoirs in Texas and throughout the United States. Efforts from this project have resulted in the development of a native plant restoration manual available to anyone free of charge at (http://www.tpwd.state.tx.us/publications/pwdpubs/media/ pwd_rp_t3200_1770.pdf). Further, the project has also been highlighted in numerous magazine articles, online videos, and television segments.
Youth Participation/education involvement:
Presentations have been given to numerous civic and conservation organizations as well as at scientific meetings. Using the example of the Lake Conroe Project TPWD is working with schools and conservation organizations to develop similar projects at Lake Houston, Lake Livingston, Lake Waco, Fort Boggy State Park Lake, and Lake Raven in Huntsville State Park. SJRA uses the habitat conservation project as a key element in the school and youth outreach program. This program includes in-class presentations, school field trips to Lake Conroe, and youth-oriented education segments on the SJRA website and in Dockline Magazine. Students from area schools also volunteer for in-lake habitat improvement including vegetation planting and structural habitat. Recently a Conroe High School Student worked with project partners to accomplish structural habitat placement as part of an Eagle Scout Project.
Community Support/Involvement:
This project was recently awarded the Texas Environmental Excellence Award in the Civic/Community category for 2013. Primary community partners are listed below.
Although the volunteer labor associated with this project is outstanding, native vegetation restoration is labor intensive. As a group, we are constantly seeking involvement from more individuals and organizations to increase the number of native vegetation founder colonies in place in the reservoir. Entergy is our most recent corporate partner with project planning underway to expand a bird sanctuary island in Lake Conroe with a constructed wetland funded by Entergy and SJRA with assistance from all partners.
Project Timeline and Costs:
This project submission covers the period 2005 -2012; however, the project is ongoing with additional vegetation planting and structural habitat improvements planned for 2013 and beyond. Significant milestones include:
• 2006 – Construction of the Lake Conroe Native Aquatic Plant Nursery.
• 2006 – 2010 – Approximately 2,500 native plants planted in Lake Conroe.
• 2006-2008 – Control of approximately 2,000 acres of exotic aquatic vegetation.
• 2011 – Construction and deployment of approximately 4 acres of structural fish habitat.
• 2011-2012 – Planting of approximately 5 miles of shoreline with native aquatic vegetation.
• 2013 – Planned activities for 2013 and beyond include:
• Planting of an additional 5 miles of shoreline with native aquatic vegetation with involvement from all partners
• Construction and placement of PVC fish attractors as part of a multi-reservoir, best management practices structural habitat research project partially funded by a RFHP Friends of Reservoirs Grant
• Creation of a constructed wetland with enhanced shoreline structure to augment the Bird Island bird sanctuary on Lake Conroe in cooperation with Entergy, SJRA, and other partners
• Evaluation of hydrilla flies as part of an integrated pest management approach in conjunction with USCOE and other partners
• Creation of a watershed protection plan for Lake Conroe in conjunction with SJRA
• Evaluation of grass carp resistance by native aquatic plants in conjunction with Texas A&M University, SJRA, USCOE, and other partners
• Evaluation of a best practices model for native vegetation restoration in conjunction with Texas A&M University, SJRA, USCOE, and other partners
• Creation and publication of a Lake Conroe Conservation and Recreation Guide in conjunction with all partners and funded and printed by Dockline Magazine
Collaborating Partners:
Seven Coves Bass Club/Lake Conroe Friends of Reservoirs Chapter, BASS, Texas BASS Federation, Dockline Magazine, San Jacinto River Authority, U.S. Army Corps of Engineers Waterways Experiment Station and Lewisville Aquatic Ecosystem Research Facility, Texas Parks and Wildlife Department, Texas Black Bass Unlimited, Texas Association of Bass Clubs, Lake Conroe Association, Toyota Texas Bass Classic, U.S. Forest Service, Texas A&M University, University of North Texas, Entergy.
Native aquatic vegetation establishment nursery and field plantings – approximately $300,000.
Exotic aquatic vegetation control - approximately $600,000.
Structural fish habitat – approximately $60,000.
Outreach, education, and publications – approximately $40,000.
Approximate total cost = $1,000,000