Geology topics

Mirtha A. Angulo-Valencia

Publications and source records attributed to Mirtha A. Angulo-Valencia.

3 recordsLinked to original sources

USGS2026

Putting weight to work: A review and examples of weight-based indicators in freshwater fish stock assessment

Despite being a direct measure of biomass and central to fisheries management, weight-based metrics remain underutilized in freshwater fish stock assessment. Here, we present a concise review of the application of weight in evaluating freshwater fish populations. We examine the historical use of weighing, assess how weight is applied across subdisciplines of freshwater fish science, contrast weight- and length-based approaches, and identify biases in their application. We then synthesize weight-based metrics, indices, and models within four broad categories—population and community weight structure; condition, growth, and efficiency; reproductive potential and production; and yield and exploitation dynamics—highlighting approaches that inform fish ecology, population and community dynamics, and vital rates. We conclude by identifying key opportunities and methodological innovations needed to expand the effective use of weight-based metrics in freshwater fish conservation and management.

North American Journal of Fisheries Management↗

USGS2026

Invasive carps versus native fish: A first-pass trait-based index for assessing competition threats.

Introduction: Bigheaded carp ( Hypophthalmichthys spp.) are invasive fish in the Mississippi River basin. Their rapid proliferation has raised concerns about exploitative competition with native fishes, with consequences that remain incompletely understood. We aimed to identify native species most susceptible to competition based on overlap with bigheaded carp in dietary and habitat traits. Methods: We used an established fish traits database to quantify dietary and habitat overlap between bigheaded carp and 100 native fish species. We then integrated dietary and habitat overlap into a composite competition index. Results: Dietary similarity with the native assemblage exceeded habitat similarity, suggesting that while competition with some native species may occur, it may often be limited by spatial separation. Dietary and habitat similarity coefficients were not correlated, indicating that strong dietary overlap did not necessarily coincide with similar habitat use (and vice versa). Approximately 20% of species were classified as high competition risk. The highest-risk species included bigmouth buffalo ( Ictiobus cyprinellus ), threadfin shad ( Dorosoma petenense ), black redhorse ( Moxostoma duquesnii ), bluntnose minnow ( Pimephales notatus ), highfin carpsucker ( Carpiodes velifer ), and gizzard shad ( Dorosoma cepedianum ). Discussion: Although trait-based predictions have limitations, our results are consistent with empirically documented interactions and provide a rapid, first-pass assessment of potential competitive vulnerability. Dietary overlap, habitat overlap, and the derived competition index offer actionable decision-support for managing potential competition between bigheaded carp and native species. We included ten practical recommendations to translate predictions into conservation and management actions.

Alabama, Kentucky, Mississippi, North Carolina, So↗

USGS2026

Reservoir cascades as directional invasion corridors

Reservoir cascades in large river systems impose directional pathways that can structure biological invasions, yet how these pathways interact with propagule supply and lock-mediated passage opportunity to influence arrival timing remains poorly understood. We used interval- and right-censored time-to-event models to evaluate spread dynamics of silver carp ( Hypophthalmichthys molitrix ) across the Tennessee River and Cumberland River reservoir cascades and test whether the timing of first detection was explained by position within the cascade, annual water locked, or accumulated propagule exposure from downstream source populations. The timing of first detection was related to distance from the invasion source, but cumulative exposure metrics offered no supplementary model support, suggesting that arrival timing was mostly associated with position within the cascade. Models incorporating annual water locked offered modest supplementary support, suggesting that lock-mediated passage opportunity may partially influence the progression of the invasion front. Spread progressed directionally but was not complete in the Tennessee River cascade, indicating that pathway structure alone does not guarantee arrival. Patterns were consistent across both rivers, suggesting that spread through reservoir cascades can follow repeatable patterns in which arrivals are constrained by downstream source populations and lock-mediated connectivity. From a management perspective, our results suggest distinct leverage points across spatial and temporal scales, including early detection and containment at downstream reservoirs, suppression of source populations to slow spread, and interventions at invasion fronts or key connectivity points to limit further expansion. Recognizing reservoir cascades as directional dispersal pathways provides a simple and transferable basis for anticipating and managing invasions in large river networks.

Tennessee↗