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Zooarchaeology is the study of animal remains (bone, shell, antler, and other organic tissues) from archaeological sites, which can provide conservation biologists with data on human–environmental interactions with greater time depth than historical records. Such data are of interest because they can be used to study whether or not contemporary animal communities (in this case of freshwater mussels) have changed in terms of species composition or range as a result of human-induced changes to habitat, which is essential for determining a species’ conservation status and formulating actions to protect remaining populations. This study considers whether or not the taxonomic composition of the freshwater mussel community from the Leon River in central Texas differs between the late Holocene and today. Specifically, we analyzed two zooarchaeological assemblages and compared those results with recent surveys conducted within the Leon River. Three species proposed for listing under the Endangered Species Act are found in the zooarchaeological record, of which two are now extirpated from the river basin (Truncilla macrodon and Fusconaia mitchelli). The results of this study provide an example of how zooarchaeological data can be used to evaluate mussel community change through time and provide evidence of range curtailment for threatened mussel species. [ABSTRACT FROM AUTHOR]

The impoundment of running waters is a threat to freshwater mussels and has only been cursorily examined in Texas. To address this, we evaluate mussel assemblage structure in the Sabine River downstream of a flood control and hydropower reservoir. We use the serial discontinuity concept (SDC) and the Life History Continuum model (LHCM) to explain relationships between stream position (i.e., downstream distance from either dam) and mussel species richness, catch-per-unit effort (CPUE), and life history strategy. Using 90th, 85th, and 80th quantile regression models, we observed that mussel species richness and abundance were reduced for stream segments located near Lake Tawakoni and Toledo Bend Reservoir and that these reductions decreased with distance from either reservoir. We also observed significant shifts in life history composition of mussel assemblages depending on stream position from either dam. Opportunistic strategists were more abundant in reaches located immediately downstream of Lake Tawakoni and Toledo Bend Reservoir whereas periodic and equilibrium strategists were most abundant in reaches located at intermediate distances from either reservoir. Findings from this study confirm the negative impact large impoundments have on downstream mussel populations and demonstrate the value of using the SDC and LHCM for evaluating mussel response to river impoundment. [ABSTRACT FROM AUTHOR]