Developing conservation strategies for migratory fishes requires an understanding of connectivity among populations. Neotropical rivers contain diverse and economically important assemblages of migratory fishes, but little is known about the population biology of most species. We examined the population structure of Prochilodus mariae, an abundant migratory fish species found in Venezuelan rivers that plays essential roles in both regional fisheries and ecosystem dynamics. By coupling otolith microchemistry and microsatellite genetic analyses, we were able to evaluate both natal origins of individual fish and genetic structure on a regional level. The chemistry of otolith cores inferred separate breeding grounds for four of six populations, with 75-85% of individuals from each river sharing 1192 MIGRATORY FISH POPULATION STRUCTURE 1193 a natal signature that is distinct from the other populations. In contrast, we detected no genetic structure, indicating that gene flow among these rivers prevents population differentiation. These disparate inferences underscore the complexity of conserving migratory species; otolith data suggest that ensuring fishery sustainability requires recognizing distinct breeding stocks, while gene flow reflects the importance of connectivity across the broader river network on an evolutionary time scale. We conclude that multiple methodological approaches may often be necessary to fully understand the spatial ecology and management needs of migratory fishes and, therefore, also influence local management practices.

Plant growth and resilience require balancing an inherently oxidative metabolism with powerful antioxidant systems that help maintain homeostasis. When the environment changes, reactive oxygen species are potent indicators of that change, allowing adaptation through re-balancing metabolism and antioxidant systems. A large body of evidence supports the use of exogenously applied antioxidants to improve both plant growth and their resilience to stress. Notably, some phenotypic effects are similar upon the application of chemically diverse antioxidants, while others are distinct. In this review, we analyze research from antioxidant treatment experiments and highlight the similarities in their practical applications and their effects on plant stress tolerance, photosynthesis, native antioxidant systems, and phytohormones. We also briefly cover the specific effects of individually applied antioxidants and what is known about their potential modes of action. Given the strong potential of antioxidant applications, we discuss research needed to promote their agricultural use. Finally, we identify outstanding questions about how the exogenous application of antioxidants mechanistically affects plant growth.

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Global raptor conservation relies on humans to establish and improve interaction and coexistence. Human–wildlife interaction research is well-established, but tends to focus on large-bodied, terrestrial mammals. The scope and characteristics of research that explores human–raptor interactions are relatively unknown. As an initial step toward quantifying and characterizing the state of applied, cross-disciplinary literature on human–raptor interactions, we use established systematic map (scoping reviews) protocols to catalog literature and describe trends, identify gaps and biases, and critically reflect on the scope of research. We focus on the peer-reviewed (refereed) literature germane to human–raptor interaction, conflict, tolerance, acceptance, persecution and coexistence. Based on 383 papers retrieved that fit our criteria, we identified trends, biases, and gaps. These include a majority of research taking place within North America and Europe; disproportionately few interdisciplinary and social research studies; interactions focused on indirect anthropogenic mortality; and vague calls for human behavior changes, with few concrete steps suggested, when management objectives are discussed. Overall, we note a predominant focus on the study of ecological effects from human–raptor interactions rather than sociocultural causes, and suggest (as others have in various conservation contexts) the imperative of human behavioral, cultural, and political inquiry to conserve raptor species.