Mark A. Webb

Lake Conroe: A Case History of Integrated Plant Management for Hydrilla Control

Lake Conroe has long been synonymous with controversial control of the exotic plant hydrilla (Hydrilla verticillata). Hydrilla was first identified in Lake Conroe in 1975, only two years after the reservoir was impounded. By the time it was identified in Lake Conroe hydrilla already occupied 190 ha. Subsequent surveys indicated hydrilla was spreading rapidly. By 1979, hydrilla had increased to over 1,821 ha in Lake Conroe and was causing significant problems for boaters, skiers, and swimmers. As a result of efforts by the Lake Conroe Association and its supporters and despite objections by...

Lake Conroe Re-vegetation: A Cooperative Management Project

Lake Conroe is located approximately 93 km north of Houston, Texas, on the west fork of the San Jacinto River in Montgomery and Walker counties. Constructed in 1973 as a joint project of the City of Houston, the Texas Water Development Board, and the San Jacinto River Authority (SJRA) to serve as an alternate water source for the City of Houston, the reservoir covers about 8,498 ha. An expanding problem with the invasive plant hydrilla (Hydrilla verticillata) in 2006 prompted the creation of the Lake Conroe Vegetation Management Plan. The Texas Parks and Wildlife Department and SJRA...

Evaluation of the Efficacy of an On-line Angler Diary

Angler surveys along with other modern research techniques provide managers with information needed to justify regulations to protect resources, to increase resources through stocking and habitat improvement, and to justify access improvement. However, Texas Parks and Wildlife (TPWD) receives little or no information from anglers concerning their activities on the majority of public waters. An online angler diary (OAD) system could substantially increase the number of water bodies from which TPWD receives at least anecdotal angler information. In order to create an efficient means of...

Evaluation of Methods for Establishing Native Aquatic Vegetation in Seven Texas Reservoirs

Aquatic vegetation plays an important role in freshwater systems, providing quality habitat for fish, sequestering nutrients, stabilizing sediments, and improving water clarity. Because many Texas reservoirs are either sparsely vegetated or contain an overabundance of non-native species such as hydrilla (Hydrilla verticillata), Texas Parks and Wildlife Department's Inland Fisheries Division began a new initiative to develop procedures for establishing diverse native aquatic plant communities. Establishment techniques were tested in seven reservoirs representing diverse geographical areas...

Precision of White Crappie Population Parameters Under Single-night and Multiple-night Frame-net Sampling Regimes

White crappie (Pomoxis annularis) stock structure and catch rate estimates and their associated variances were compared between 1-night and 3-night frame-net sets. We set paired frame nets at each of 5 stations on 3 reservoirs in fall and early winter 1990. We ran 1 net of each pair the morning after it was set; the second net of each pair was allowed to fish for 3 nights continuously. PSD and RSDp estimates from each sampling regime were similar. Three night sets significantly increased precision of PSD estimates. Both 1-night and 3-night sets yielded similar estimates of CPUES, CPUEq,...