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Quagga (Dreissena rostriformis bugensis) and Zebra (Dreissena polymorpha) mussels are highly invasive and easily transported from one waterybody to another. California has an extensive program designed to prevent the spread of these mussels. This program is coordinated by the California Department of Fish and Wildlife (CDFW) Invasive Species Program, within the Habitat Conservation Planning Branch. This data set summarizes the locations of Quagga and Zebra mussel findings within California waterbodies, using data from the U.S. Geological Surveys NAS (Nonindigenous Aquatic Species) database.

Data is a spreadsheet of the number of copies of Zebra Mussel DNA detected and the number of positive detections for Zebra Mussel DNA from water samples collected over 6 different substrates, at 4 depths in 2 lakes. The ash-free dry weight of the mussels at each of the sites is also included for each sampling location.

Impacts of dreissenid mussels (Dreissena spp.) on Great Lakes ecosystems are well documented, and a better understanding of mechanisms that cause variation in mussel abundance is needed. An outstanding question is how much mussel biomass is consumed by fish predation. A significant difficulty for investigating mussel consumption by fish is that mussels in stomachs are often a mix of crushed shell and flesh. Here, we provide information on the relationship between shell-and-flesh dry weight measurements and flesh-only dry weight of two species of dreissenid mussel, quagga (Dreissena rostiformis bugensis) and zebra (Dreissena polymorpha), to be used in formulating conservative estimates of flesh-only dry weight in fish diets. Dry weight analyses were conducted to simulate stomach contents ranging from small (individual mussels) to large (aggregate of mussels). All measurements were taken at the USGS Lake Erie Biological Station in Sandusky, Ohio using quagga and zebra mussels collected from Lake Erie in May, 2014.

Dispersal, establishment, and spread of aquatic invasive species such as the zebra mussel (Dreissena polymorpha) can be influenced by riverine velocities and volumetric flows in invaded lake-stream ecosystems. Zebra mussels, which have a planktonic larval form (veliger), disperse rapidly downstream from a source population. Concentrations, dispersal, and body conditions of zebra mussel veligers were studied under different volumetric flow, or discharge, conditions in a coupled lake-stream ecosystem in northern Texas, USA. Veliger densities in lotic environments were strongly related to population dynamics in upstream lentic source populations. A strong exponential decrease in veliger density was observed through a 28-km downstream study reach. Increased water releases from the source reservoir increased veliger flux and dispersal potential, concomitantly increasing veliger flux and decreasing transit time. However, passage through release gates in the dam and increased turbulence in the river during high-discharge events could negatively affect body condition of veligers, and veliger body condition generally decreased from the source population to the farthest downstream site and was lower for veligers during periods of high discharge. Thus increased discharge appears to reduce the proportion of viable veligers because of increased turbulence-induced mortality. Colonization of distant downstream reservoirs can occur if discharge and propagule pressure are sufficient or if interim habitats are suitable for establishment of in-stream populations.

In response to the growing concerns among Native communities about the safety of subsistence shellfish, this project assessed the health risks associated with consuming softshell clams, mussels and cockles. The aforementioned shellfish were collected in traditional harvest area in Resurrection Bay, AK and analyzed for contaminant body burdens and for occurrences of pathogens and diseases. A broad suite of contaminants were analyzed including 55 Polycyclic Aromatic Hydrocarbons (PAHs) , 27 chlorinated pesticides including DDT and its break-down products, 37 Polychlorinated Biphenyls (PCBs), 16 major and trace elements (Ag, Al, As, Cd, Cr, Cu, Fe, Hg, Mn Ni, Pb, Sb, Se, Sn and Zn), and tributyl-tin and its break-down products. The health of the subsistence shellfish were further characterized based on the presence an array of about 30 parasite taxa (e.g. bucephalus, chlamydia, ciliates, cestodes and nematodes) and occurrence of 11 diseases (e.g. MSX, tumors, neoplasm, edema and necrosis), which were quantified using prevalence and intensity computation. Results indicated that: - A great variation in metal body burdens among the different subsistence shellfish studied. Mercury was measured in all shellfish, but with the maximum value (0.2 ppm) found in blue mussels. Maximum tissue concentration for toxic metals such as chromium and Nickel were recorded in cockles. Maximum values for cadmium were found in mussels and softshell clams, while that of lead was found in the blue mussels. - Organic contaminants were detected in all subsistence shellfish although many of these compounds were banned more than three decades ago. - Metal and organic contaminant body burden were in general very low relatively to U.S. Food and Drug Administration guidelines for seafood safety. - Among the parasites assessed only large gill ciliates, small gill ciliates and gut rickettsia were detected in clam and blue mussels. - Among the bivalve diseases and tissue pathologies characterized in this study, digestive tubule atrophy was the most prevalent with 100% occurrence in cockles and mussels and about 96% in clams. Disease, such as ceroid bodies and histological condition such as diffuse and focal inflammations were also measured, but at relatively lower count than the digestive track atrophy. - In general, all infections and tissue pathology in the shellfish were minor and the conditions do not appear to be either a threat to the health of the shellfish or to humans that consume them. As a part of this study interspecies concentration factors (ICFs) that relate chemical concentrations in mussels to those in subsistence shellfish, were determined. The intent is to use ICFs as factor to evaluate contaminant concentrations in a wide range of Alaskan shellfish based upon measurements obtained for one species, thereby eliminating the need to monitor all species. Concentration values for many compounds were low or not detected, but where possible ICFs were calculated. This project provides invaluable baseline chemical body burden data on shellfish species that is geo-referenced and posted on the internet through the NOAA's National Status and Trends data portal.

These data represent environmental DNA detections of freshwater mussels in the Green River, KY, USA; West Virginia long-term water quality monitoring sites, USA; and the Chesapeake Bay and Potomac basin, Maryland, USA. “This research dataset has been reviewed in accordance with U.S. Environmental Protection Agency (U.S. EPA), Office of Research and Development, and approved for release. Mention of brand names or vendors does not constitute an endorsement of products or services by the U.S. EPA.”"

Zebra mussels (Dreissena polymorpha Pallas 1771) are a tenacious aquatic invasive species in the United States and new infestations can rapidly expand into dense colonies. Zebra mussels were first reported in Marion Lake (Dakota County, Minnesota) in September 2017 and surveys indicated the infestation was likely isolated near the public boat access. A 2.4-hectare area, containing the known zebra mussel infestation, was enclosed and treated for nine days with EarthTec QZ®, a copper-based molluscicide, in an attempt to eradicate the zebra mussels. We conducted an on-site bioassay to confirm treatment efficacy. The bioassay was conducted in mobile assay trailer that received a continuous flow of treated lake water and zebra mussels test animals that were collected from White Bear Lake (Ramsey County, MN). Zebra mussel mortality in the treated bioassay tanks achieved 99 percent mortality (95-percent Confidence Interval: 98 – 100 percent) and a predictive model indicates in-lake mortality as low as 85 percent may have occurred; therefore, our results indicate that the Marion Lake treatment may not have induced complete zebra mussel mortality. Post-treatment assessments and surveys are recommended to further verify treatment success and monitor lake conditions in regards to zebra mussel infestation.