The Centers of Research Excellence in Science and Technology-Postdoctoral Research Fellowship (CREST-PRF) supports beginning CREST Center investigators and provides them with training and research experiences that will broaden perspectives, facilitate interdisciplinary interactions and establish them in positions of leadership within the scientific community. The CREST-PRF research project titled "Cross-Ecosystem Interactions and the Transport of Aquatic Contaminants to Terrestrial Food Webs within Mangrove Forests" is aligned with the goals of the CREST-Center for Aquatic Chemistry and Environment at Florida International University through its study of contamination of mangrove forests due to urbanization and natural causes. Because of their unique location at the intersection of freshwater, marine, and terrestrial ecosystems, mangroves serve as critical habitat for a wide range of aquatic and terrestrial organisms, while also providing important ecological services. The specific aims of this research is to characterize how mangrove food webs are affected by urbanization, as well as to measure the concentrations of contaminant metals moving from aquatic to terrestrial ecosystems via aquatic insects. The study is supported through the collaborative efforts of several research institutions and universities from southern Florida and Puerto Rico. Training of undergraduates and graduate students in conducting and disseminating research is part of the project's work, as is outreach to K-12 students and teachers and the general public, to enhance their understanding of important environmental issues that are relevant to their communities.

The transfer of energy in the form of spatial subsidies (i.e. prey, detritus or nutrients) between aquatic and terrestrial food webs is critical for maintaining biodiversity and ecological functions within mangrove ecosystems. Natural and anthropogenic disturbances have significant effects on cross-ecosystem interactions by altering physical-chemical parameters in aquatic ecosystems. This study employs field studies and chemical analyses to delineate how urbanization affects cross-ecosystem interactions and the transport of aquatic contaminants to terrestrial food webs within mangrove forests during wet and dry seasons. Field work includes sampling urban and non-urban mangrove sites in southern Florida and Puerto Rico to determine significant changes in the composition of aquatic insect and orb-weaving spider assemblages, as well as to quantify the dietary contribution of aquatic insects and their correlation with concentrations of metals in orb-weaving spiders using stable isotope and trace metal analyses. In addition, bioassays are used to measure the effects on growth and emergence rates of non-biting midges (Diptera: Chironomidae) in response to increasing levels of salinity and metals. The taxa of aquatic insects and spiders that are the focus of the research have worldwide distributions and therefore findings can be used as a comparative model for other mangrove ecosystem studies around the globe.

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.

National Science Foundation (NSF)
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Victor Santiago
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Kelly, Sean Patrick
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