CAREER: The Plastisphere of Pond Ecosystems: Understanding the function and fate of novel carbon in biogeochemical hotspots

Plastics represent a form of novel carbon, solid waste, and debris. Most plastics travel through freshwater environments to the ocean, making ponds an important place to study the impact of this novel carbon source. Ponds are widespread across various landscapes and provide many important services. Most notably, ponds provide resilience by capturing and removing storm water, carbon materials, solid waste, and debris. Depending on size and age, ponds can be sites of where carbon is emitted or stored, which is important regarding emissions of gasses to the atmosphere. Therefore, pond ecosystem services may be altered by captured plastic debris. The prolonged storage of plastic debris in ponds allows for the breakdown of plastic litter into smaller particles recognized as microplastics (particles <5mm). There are no current estimates of how long plastic and microplastic debris are retained in pond ecosystems. Thus, the unknown storage and breakdown of plastics can also release dissolved organic carbon, stimulating or inhibiting microbial activity that governs the ecosystem services ponds render to society. This award investigates the influence common plastic items have on microbial community structure in ponds, as these novel carbon sources provide a substrate for microorganisms (known as the plastisphere). The project will characterize biofilm succession on plastic and natural items and assess whether plastic-derived organic matter stimulates or inhibits microbial activity that governs ecosystem processes. Lastly, a mass-balance model will be developed to understand pond plastic and microplastic capture and removal. The integrated research and teaching program will provide environmental science to undergraduate students through field research opportunities, training in visual arts, and outreach to high school students. This award will provide foundational knowledge regarding how pond ecosystems respond to plastic pollution and understand the magnitude of response from various levels of ecological organization. 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.