Benthic ecosystem function responses to plasticizer content in polyester and PVC

Plastics are ubiquitous contaminants in marine systems with a diverse set of chemical components. While eco-toxicological effects of plastic chemicals provide insights on how marine species respond to plastic exposure, there is lack in ecological understanding of such impacts. In a mesocosm experiment, we measured benthic fluxes to determine ecosystem function responses to polyester netting (low plasticizer concentration) and PVC netting (high plasticizer concentration). Gross primary production rates and ammonium efflux were higher in both plastic treatments compared to the control, but responses were stronger in the polyester treatment. In the PVC treatment we additionally observed a strong response in nitrate fluxes which suggests a disturbance of the benthic N cycle. Our results imply that the concentration of chemical additives in new plastics can be a driver for ecological responses and reduction of plastic emissions needs to remain at the forefront of environmental plastic pollution regulations.