32. Lake Conroe, Texas
Project Submission by: The Reservoir Fish Habitat Partnership
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.