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Leveraging Museum-Preserved Fishes for Understanding Spatiotemporal Changes in Mercury Sources from Aquatic Ecosystems
Citation:
Lepak, R., S. Janssen, J. Hoffman, C. Yarnes, J. Ogorek, M. Tate, C. Dillman, AND P. McIntyre. Leveraging Museum-Preserved Fishes for Understanding Spatiotemporal Changes in Mercury Sources from Aquatic Ecosystems. 2022 Joint Meeting of Ichthyologists and Herpetologists, Spokane, WA, July 27 - 31, 2022. https://doi.org/10.23645/epacomptox.20493054
Impact/Purpose:
Presentation to the Joint Meeting of Ichthyologists and Herpetologists July 2022. Fieldwork in remote regions of the world can be expensive and often data collected only represents a snapshot in time. Museum specimens provide researchers unmatched spatiotemporal coverage when performing research on fish. We designed a method to measure methylmercury stable isotope ratios in liquid preserved fishes which allows us to ask new questions about mercury sources across vast domains. Here we present that method and then its application to a case study on the Congo River, Africa.
Description:
Remarkable archives of biota are preserved in natural history museums across the globe. These collections can aid the challenge of sampling remote aquatic ecosystems yet have never been used for large-scale assessment of mercury contamination. Using biota rather than sediment cores to infer temporal shifts in mercury bioaccumulation will sidestep assumptions about bioavailability that have complicated previous approaches. Previously, methylmercury concentrations in museum bird feathers have allowed us to reconstruct historical mercury burden to birds. Fishes are the prized sentinel to tracking shifts in mercury dynamics but because they are liquid preserved, making similar reconstructions is challenging. While we haven’t fully resolved how preservation and curation protocols impact mercury concentrations in fishes, we have developed a method that allows us to measure mercury stable isotopes in museum preserved fishes and thus infer mercury sources to these ecosystems. Here, we briefly describe this approach and then discuss its application in tropical central Africa from 1900 to present. With this new approach we hope to disentangle the changes in mercury sources to fishes as the region has diversified economically and in its resource exploitation. This will aid in better establishing baselines and predicting the impact of future changes at varying scales (e.g., climate, continued exploitation).
URLs/Downloads:
DOI: Leveraging Museum-Preserved Fishes for Understanding Spatiotemporal Changes in Mercury Sources from Aquatic Ecosystems
JMIH DILLMAN 072522.PDF (PDF, NA pp, 4602.809 KB, about PDF)