We applied Zequanox using a custom-engineered, boat mounted application system to replicated 0.30 Hectare plots within a small inland lake. The objectives of these applications were to determine if uncontained, open-water Zequanox applications could effectively control zebra mussel populations and protect native unionid mussel populations within zebra mussel infested systems. The datasets included are as follows: Exposure Water Chemistry Hardness and Alkalinity Native Mussel Sonde Water Chemistry Zebra Mussel Density Zebra Mussel Length Zebra Mussel Mortality Zequanox Concentration ShapeFiles: PLOTS, UNIONID, ZEQUANOX CONCENTRATION, ZM_DENSITY, ZM_MORTALITY

We applied Zequanox using a custom-engineered, boat mounted application system to replicated 0.30 Hectare plots within a small inland lake. The objectives of these applications were to determine if uncontained, open-water Zequanox applications could effectively control zebra mussel populations and protect native unionid mussel populations within zebra mussel infested systems. The datasets included are as follows: Exposure Water Chemistry Hardness and Alkalinity Native Mussel Sonde Water Chemistry Zebra Mussel Density Zebra Mussel Length Zebra Mussel Mortality Zequanox Concentration ShapeFiles: PLOTS, UNIONID, ZEQUANOX CONCENTRATION, ZM_DENSITY, ZM_MORTALITY

We applied Zequanox using a custom-engineered, boat mounted application system to replicated 0.30 Hectare plots within a small inland lake. The objectives of these applications were to determine if uncontained, open-water Zequanox applications could effectively control zebra mussel populations and protect native unionid mussel populations within zebra mussel infested systems. The datasets included are as follows: Exposure Water Chemistry Hardness and Alkalinity Native Mussel Sonde Water Chemistry Zebra Mussel Density Zebra Mussel Length Zebra Mussel Mortality Zequanox Concentration ShapeFiles: PLOTS, UNIONID, ZEQUANOX CONCENTRATION, ZM_DENSITY, ZM_MORTALITY

We applied Zequanox using a custom-engineered, boat mounted application system to replicated 0.30 Hectare plots within a small inland lake. The objectives of these applications were to determine if uncontained, open-water Zequanox applications could effectively control zebra mussel populations and protect native unionid mussel populations within zebra mussel infested systems. The datasets included are as follows: Exposure Water Chemistry Hardness and Alkalinity Native Mussel Sonde Water Chemistry Zebra Mussel Density Zebra Mussel Length Zebra Mussel Mortality Zequanox Concentration ShapeFiles: PLOTS, UNIONID, ZEQUANOX CONCENTRATION, ZM_DENSITY, ZM_MORTALITY

We applied Zequanox using a custom-engineered, boat mounted application system to replicated 0.30 Hectare plots within a small inland lake. The objectives of these applications were to determine if uncontained, open-water Zequanox applications could effectively control zebra mussel populations and protect native unionid mussel populations within zebra mussel infested systems. The datasets included are as follows: Exposure Water Chemistry Hardness and Alkalinity Native Mussel Sonde Water Chemistry Zebra Mussel Density Zebra Mussel Length Zebra Mussel Mortality Zequanox Concentration ShapeFiles: PLOTS, UNIONID, ZEQUANOX CONCENTRATION, ZM_DENSITY, ZM_MORTALITY

The environmental fate, persistence, and point-source discharge of traditional molluscicidal compounds led to the development of an alternative biomolluscicide, Zequanox. Previous studies evaluated the efficacy and non-target animal safety of Zequanox in laboratory, mesocosm, and field enclosure studies. One study indicated sensitivity of salmonid species and lake sturgeon (Acipenser fulvescens Rafinesque 1817) following exposure to Zequanox, however, the exposures were not conducted in a manner consistent with the product label. This laboratory study evaluated sublethal and lethal impacts of Zequanox on lake sturgeon and lake trout (Salvelinus namaycush Walbaum in Artedi, 1792) following exposures that were conducted consistent with a Zequanox open-water label application. Fish were exposed to 50 and 100 mg Zequanox active ingredient/L for 8 h and then held for an additional 33-d for post-exposure observation. No acute mortality was observed in either species, however, significant latent mortality (46.2%) was observed in lake trout that were exposed to 100 mg of Zequanox active ingredient/L for 8 h. At the termination of the 33d holding period, biologically minimal, yet statistically significant, differences were observed in the terminal weight of surviving lake sturgeon (range 20.17 to 21.49 g) and biologically, as well as, statistically significant differences were observed in the terminal weight of surviving lake trout (range 6.19 to 9.55 g). Histological evaluation of lake trout gastrointestinal tracts suggest that a different mode of action is responsible for the Zequanox exposure-related impacts to lake trout than the mode of action that induces zebra and quagga mussel mortality. Further research is required to determine if Zequanox sensitivity is limited to lake trout or if all salmonid species are vulnerable to exposure and to determine if native fish will avoid Zequanox exposure.

We applied habitat suitability indices and network analysis to identify the lakes most critical to the establishment and spread of zebra mussels (Dreissena polymorpha). We included 225 lakes in the study area Habitat suitability indices were based on known tolerances of water chemical and physical parameters in relationship to zebra mussel growth, survival, and reproduction. We created multiple boater movement networks consisting of lake nodes and connecting roadway edges. Each network represented the potential connectivity of lakes for recreational users depending on the maximum roadway distance boaters were likely to travel. We evaluated three different maximum roadway distances based on boater movement surveys: 95% of boaters traveled within 363 km, 75% traveled within 125 km, and 50% traveled within 51 km. We recorded centrality measures of graph analysis, to help identify lakes critical to the spread of zebra mussels by acting as hubs (i.e., degree score), stepping stones (i.e., betweenness centrality), or cutpoints. We also documented each lake's infestation status as of March 2024.

Zebra mussels are representative of nonindigenous aquatic species (NAS) with devastating economic, recreational, and environmental impacts that are already under watch as a problematic species across the U.S. and in Texas. Targeting dispersal pathways is likely the most efficient means of controlling their spread further west. The movement of recreational watercraft is one of the main vectors for the spread of zebra mussels and other NAS among lakes. Thus, we created a risk assessment to guide monitoring efforts to detect and report new sightings of zebra mussels and other NAS. Lake risk scores were based on the potential establishment and spread of zebra mussels. Lake establishment risk was determined by applying a habitat suitability index (HSI) of water physicochemical parameters compiled from preexisting sources and supplemental field collection (Child Item 1: "Water physicochemical parameters of twenty Texas and New Mexico lakes 2022-2023"). The risk of spreading zebra mussels from a lake was determined by centrality measures of network analysis to identify lakes acting as hubs (degree score), stepping stones (betweenness score), and cutpoints. We applied network analysis at three different maximum roadway distances based on the 95th , 75th , and 50th percentiles of boater movement. The combination of HSI and centrality scores (Child Item 2: "Habitat suitability scores, network scores, and infestation status for 225 lakes in Texas and New Mexico") were used to identify potential high risk lakes.

Zebra mussels (Dreissena polymorpha) have continued their spread within inland lakes and rivers in North America despite diligent containment and decontamination efforts by natural resource agencies and other stakeholders. Identification of newly infested waterways with early detection surveillance programs allows for rapid response zebra mussel eradication treatments in some situations. Previous eradication treatments have been conducted during times of variable water temperatures and temperature has been shown to influence the efficacy of molluscicides. Natural resource managers would benefit from knowledge regarding the impacts of water temperature and exposure duration on toxicity of molluscicides to zebra mussels. In particular, temperature specific data are needed to inform the selection of an effective molluscicide and the proper dose that will induce 100% zebra mussel mortality. We evaluated the influences of temperature and exposure duration on the toxicity of two EPA-registered (EarthTec QZ and Zequanox) and two nonregistered (niclosamide and potassium chloride) molluscicides to zebra mussels at water temperatures of 7, 12, 17, and 22 °C. Our results indicate that treatment options for the eradication of zebra mussels in waters ≤ 12 °C include 336 h or longer treatments with EarthTec QZ and KCl and treatments with niclosamide ≥ 24 h in duration. In waters ≥ 17 °C, multiple toxicant and exposure duration combinations would be effective for zebra mussel eradication treatments. However, site specific variables should be considered prior to treatment including: the extent of the infestation, water chemistry, aquatic vegetation, substrate, and the presence of nontarget organisms. The use of on-site or in situ zebra mussel bioassays would also be a useful tool for the evaluation of treatment efficacy. The dataset includes: Water Quality, Chemical Concentrations, Mortality, and Zebra Mussel Condition Data

The purpose of this data release and associated data series (Carr and Fancher, in review) was to compile occurrence records and map the distribution of a freshwater mussel assemblage for the Bureau of Land Management Rapid Ecoregional Assessment for the Southern Great Plains. The freshwater mussel assemblage includes Amblema plicata (threeridge), Fusconaia flava (Wabash pigtoe), Lampsilis cardium (plain pocketbook), Lampsilis teres (yellow sandshell), Pyganodon grandis (giant floater), and Uniomerus tetralasmus (pondhorn). The focal species in the assemblage were selected based on the following criteria: (1) the species are regionally significant, (2) occurrence records are sufficient to map the distribution of the species by hydrological subbasins, (3) the status of each species includes a range of State-level conservation priorities, and (4) the species are not listed as federally endangered or threatened. The six focal species represent a broad array of life history traits and habitat associations. The contemporary distribution (survey dates: 1970 to 2017) were mapped at two spatial scales: hydrological subbasins and subregions within the Missouri and Arkansas-White-Red Regions. Historical records (occurrence record dates: 1885 to 1962) were also compiled but were limited. This data release summarizes occurrence records for the freshwater mussel assemblage by the 8-digit hydrologic unit code, which identifies the region, subregion, and subbasin. For each subbasin, the data release provides occurrence information for each of the six focal species, including the data source, time period, and number of records. Such multiscale baseline information can be useful for evaluating mussel population status and trends, identifying potential restoration areas, and providing the broader context for in-depth studies within watersheds, reaches, and subcatchments. Additional background information, methods, dataset limitations, and graphical representations of this data release, are provided in the associated data series available at https://doi.org/ 10.3133/ ds1133.