NSF Postdoctoral Fellowship in Biology: Chironomid Bioturbation at Future High Temperature Scenarios and its Effect on Nutrient Fluxes and Bacterial Activity

Reyes Maldonado, Roberto, San Juan PR

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2023, Broadening Participation of Groups Underrepresented in Biology. The Fellowship supports a research and training plan for the Fellow that will increase the participation of groups underrepresented in biology. Chironomid larvae are aquatic insects that play an important role in mixing and disturbing benthic sediments in a process called bioturbation. Chironomids are known for their ventilation activities, an action that promotes oxygenation, nutrient flux, and bacterial activity in sediments. There is a lack of understanding about how chironomid bioturbation mediated processes will be affected under climate change scenarios. This should be addressed to anticipate how bioturbation induced processes would affect the balance of freshwater ecosystems in a warmer environment. This project will use an urban aquatic environment as a climate change surrogate scenario to determine the effect of high temperatures on the bioturbation behavior of chironomids and their influence on nutrient cycling and bacterial activity. Determining this will help to propose mitigation and management activities for freshwater ecosystems in the future, especially for tropical ecosystems where processes might be more sensitive to small changes in temperature. This research will also provide training opportunities to underrepresented individuals to encourage them to pursue a career in aquatic ecology or any other related field. The objective of this project will be achieved by studying microcosms maintained with the sediments and the environmental conditions of an urban stream with records of high temperature fluctuations in Puerto Rico. First, the Fellow will integrate flow velocity microelectrodes, conductivity, and color tracer techniques to determine if chironomid ventilations are affected by temperature; then, sediment core incubations will be used to determine if the effects of bioturbation on nitrogen, phosphorous, and carbon fluxes are temperature-independent; and last, molecular techniques will be used to determine how bioturbation-induced microbial activity and community composition are influenced by warm temperatures. Through the completion of this project, the Fellow will gain experience as an independent researcher, but will also promote broadening participation and inclusion in biology by providing lectures and mentoring opportunities to students and teachers in Puerto Rico. The Fellow will focus on training interested individuals in field and laboratory techniques, critical thinking, and communication skills so that they can be prepared when venturing into any scientific field in the future. 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.