EAGER: Using museum specimens to disentangle the impacts of climate change on body-size across species in freshwater fish communities.

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

Climate change is predicted to shrink body sizes and in doing so alter interactions between species and their environment with implications for survival, reproduction, and ecosystem services (including nutrient transport and food provisioning). Evidence suggests that not all species are equally impacted by climate change. But our understanding of changes in fish size and the underlying process of growth are primarily from fisheries records and do not represent the range of fish diversity. This project aims to examine patterns of growth across decades of environmental change and across a group of freshwater fish species with different traits and ecological roles in order to clarify the drivers of vulnerability to climate change. Outreach and education components of the project include developing K-12 activities and building an online Story Map to share research findings. The project also incorporates mentored undergraduate research aimed at training and retaining diverse students in museum science, data analysis and modeling, and ecological research. The research will use a combination of museum specimens, data from historical fisheries and surveys to improve our understanding of the impacts of climate on fish growth. Focusing on species which are common in northern temperate lakes, the researchers will examine patterns of growth across the last century and across gradients in temperature and growing season length, while accounting for other factors which can influence fish growth including water clarity, productivity, density-dependent species interactions, and fishing pressure. Fish growth is recorded in hard structures, including scales, which have rings delimiting growth periods between years. Therefore, museum specimens hold evidence of changes in growth rates across time and space. In this project, age at capture size (length-at-age, a measure of growth) will be estimated using non-destructive scale samples of thousands of museum specimens. Estimates will be validated by comparisons across different aging structures and from fresh specimens. By examining species which vary in evolutionary history, maximum size, thermal guilds, life history, and feeding characteristics, researchers will identify which traits are associated with climate-related changes in growth. Finally, statistical models will be used to test for changes in growth across life stages and disentangle climate effects from those of other environmental conditions, density-dependent ecological interactions, or sampling biases. By identifying the characteristics that put species at risk and the conditions driving changes in fish populations and communities, this research will inform the conservation and management of freshwater fishes. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.