Publications [#374369] of Emily S. Bernhardt

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  1. Sayers II, Christopher J. and Evers, David C. and Ruiz-Gutierrez, Viviana and Adams, Evan and Vega, Claudia M. and Pisconte, Jessica N. and Tejeda, Vania and Regan, Kevin and Lane, Oksana P. and Ash, Abidas A. and Cal, Reynold and Reneau, Stevan and Martinez, Wilber and Welch, Gilroy and Hartwell, Kayla and Teul, Mario and Tzul, David and Arendt, Wayne J. and Torrez, Marvin A. and Watsa, Mrinalini and Erkenswick, Gideon and Moore, Caroline E. and Gerson, Jacqueline and Sanchez, Victor and Purizaca, Raul Perez and Yurek, Helen and Burton, Mark E. H. and Shrum, Peggy L. and Tabares-Segovia, Sebastian and Vargas, Korik and Fogarty, Finola F. and Charette, Mathieu R. and Martinez, Ari E. and Bernhardt, Emily S. and Taylor, Robert J. and Tear, Timothy H. and Fernandez, Luis E., Mercury in Neotropical birds: a synthesis and prospectus on 13 years of exposure data, ECOTOXICOLOGY, vol. 32 no. 8, SI (October, 2023), pp. 1096-1123, SPRINGER [doi] .
    (last updated on 2023/12/08)

    Abstract:
    Environmental mercury (Hg) contamination of the global tropics outpaces our understanding of its consequences for biodiversity. Knowledge gaps of pollution exposure could obscure conservation threats in the Neotropics: a region that supports over half of the world's species, but faces ongoing land-use change and Hg emission via artisanal and small-scale gold mining (ASGM). Due to their global distribution and sensitivity to pollution, birds provide a valuable opportunity as bioindicators to assess how accelerating Hg emissions impact an ecosystem's ability to support biodiversity, and ultimately, global health. We present the largest database on Neotropical bird Hg concentrations (n = 2316) and establish exposure baselines for 322 bird species spanning nine countries across Central America, South America, and the West Indies. Patterns of avian Hg exposure in the Neotropics broadly align with those in temperate regions: consistent bioaccumulation across functional groups and high spatiotemporal variation. Bird species occupying higher trophic positions and aquatic habitats exhibited elevated Hg concentrations that have been previously associated with reductions in reproductive success. Notably, bird Hg concentrations were over four times higher at sites impacted by ASGM activities and differed by season for certain trophic niches. We developed this synthesis via a collaborative research network, the Tropical Research for Avian Conservation and Ecotoxicology (TRACE) Initiative, which exemplifies inclusive, equitable, and international data-sharing. While our findings signal an urgent need to assess sampling biases, mechanisms, and consequences of Hg exposure to tropical avian communities, the TRACE Initiative provides a meaningful framework to achieve such goals. Ultimately, our collective efforts support and inform local, scientific, and government entities, including Parties of the United Nations Minamata Convention on Mercury, as we continue working together to understand how Hg pollution impacts biodiversity conservation, ecosystem function, and public health in the tropics. We summarized the largest database on Neotropical bird Hg concentrations to identify major patterns of pollution exposure to terrestrial biodiversity in the tropics.We detected the highest Hg concentrations in carnivorous bird species, aquatic habitats, and gold mining sites.We showcase among the highest published Hg concentrations for songbirds (Passeriformes) in the world.Madre de Dios, Peru, central Belize, and Ayapel, Colombia are biological Hg hotspots, but widespread sampling is necessary throughout the Neotropics.Inclusive collaboration will excel the field of tropical ecotoxicology by improving the efficiency and comparability of future monitoring efforts. La contaminacion ambiental por mercurio (Hg) en los tropicos supera nuestra comprension de sus consecuencias para la biodiversidad. Los vacios de conocimiento que existen sobre la exposicion a la contaminacion podrian ocultar las amenazas para la conservacion en el Neotropico: una region que alberga a mas de la mitad de las especies del mundo, pero que enfrenta una continua intensificacion de las emisiones de Hg y del cambio de uso del suelo por el avance de la mineria de oro artesanal y de pequena escala (MAPE). Debido a su distribucion global y su sensibilidad a la contaminacion, las aves brindan una oportunidad valiosa como bioindicadores para evaluar como las emisiones de Hg afectan la capacidad de un ecosistema para sustentar la biodiversidad y, en ultima instancia, la salud global. Presentamos la mas grande base de datos sobre concentraciones de Hg en aves Neotropicales (n = 2,316) para establecer una linea base para los niveles de exposicion a Hg en 322 especies de aves de nueve paises de America Central, America del Sur, y el Caribe. Encontramos patrones de las concentraciones de Hg en aves de los tropicos que se asemejan a los de las regiones templadas: mostrando una bioacumulacion consistente a traves de grupos funcionales y una alta variacion espaciotemporal. Las especies de aves que ocupan posiciones mas altas en la cadena trofica y en habitats acuaticos registraron concentraciones elevadas de Hg que podrian tener efectos negativos en su exito reproductivo. Es importante resaltar que las concentraciones de Hg en las aves de los sitios afectados por la MAPE fueron cuatro veces mas altas que las de los sitios control y ademas difirio por temporada para ciertos nichos troficos. Desarrollamos esta sintesis a traves de una red de investigacion colaborativa, la Iniciativa de Investigacion Tropical para la Conservacion y Ecotoxicologia Aviar (TRACE), que ejemplifica un intercambio de datos inclusivo, equitativo e internacional. Si bien nuestros hallazgos sugieren una necesidad urgente de evaluar los sesgos en el muestreo, los mecanismos, y las consecuencias de la exposicion al Hg en las comunidades de aves tropicales, la Iniciativa TRACE proporciona un marco para abordar estos objetivos. Nuestro esfuerzo colectivo tiene como proposito respaldar y brindar informacion a las entidades locales, cientificas, y gubernamentales, incluyendo las Partes de la Convencion de Minamata de las Naciones Unidas sobre el Mercurio, mientras continuamos trabajando juntos para comprender como la contaminacion por Hg en los tropicos puede afectar la salud publica, el funcionamiento de los ecosistemas, y la conservacion de la biodiversidad.Graphical AbstractTotal mercury (THg) concentrations (mu g/g) and sample sizes of birds across Central America, South America, and the West Indies from 2007-2023. Point size and color are arranged in order of increasing THg concentration and hexagonal grid cells are colored in terms of increasing sample size.