Disease ecology in the midst of anthropogenic stressors: Exploring the influence of pollutants on host-parasite interactions 

Intellectual Merit: The effects of anthropogenic activities on natural ecosystems, including contamination by pollutants, have created a diversity of challenges for wildlife populations. Increasing evidence suggests that some wildlife populations can persist in the face of pollutants by evolving tolerance. However, maintaining tolerance to pollutants may come at a cost that influences how wildlife interact with other organisms in their environment. This project integrated the fields of global change biology, evolution, and disease ecology to understand how wildlife populations evolve in response to pollutants and the ecological consequences of evolving tolerance to pollutants on host-parasite interactions. We found: (1) Variation in tolerance to pollutants (i.e., pesticides, salt) is widespread across both amphibian and parasite populations, (2) Both amphibian and parasite populations can achieve pollutant tolerance in different ways- For some populations, pollutant tolerance is always expressed (selection for constitutive tolerance) and for others pollutant tolerance is only expressed when cued by the presence of the pollutant (phenotypic plasticity- inducible tolerance), (3) Exposure of amphibian hosts to pollutants (pesticides, road salts, microplastics, light pollution, antibiotics) affected their susceptibility to their parasites with some pollutants increasing parasite susceptibility and others decreasing parasite susceptibility, (4) Other global change factors (invasive species and temperature shifts) also interacted with pollutants to alter how organisms respond to their parasites, (5) The effects of pollutants on host susceptibility to parasites may be related to physiological changes (stress hormones) or shifts in host-associated microbial communities (microbiotas). Collectively, results from this work will contribute to building a broader and more mechanistic understanding of the cascading ecological consequences of evolutionary responses to anthropogenic activities.

Broader impacts: There continues to be public awareness and concern over the effect of anthropogenic activities on natural systems. The insights gained from this project contribute to addressing these issues at the forefront of public interest. First, this work contributed new scientific discoveries regarding how populations are likely to respond and adapt to ubiquitous anthropogenic challenges and the consequences of widespread ecosystem contamination. Results from this project was disseminated widely through publications, formal presentations at conferences and seminars, and informal publications on web pages and popular press venues. This project also contributed significant training opportunities across multiple educational levels, including high school teachers, undergraduate students, graduate students, and a post-doc. Additionally, the project contributed several publicly available resources that will be useful for K-12 teachers and students. These products include 6 lesson plans consistent with state-level learning outcomes and a children's book to help engage and teach K-5 students about ecological and global change topics. We also conducted several online and in-person teacher’s workshops. Lastly, we conducted an interdisciplinary training workshop will help students develop a foundation for dialogue across disciplines with the goal of facilitating future integration between traditionally siloed areas of research. Collectively, the results from this project resulted in integrative effects both in the fields of ecology, evolution, and global change biology as well as contributed more broadly at the societal level.

Last Modified: 03/03/2023
Modified by: Jessica Hua