Investigation of polyethylene terephthalate (PET) drinking bottles as marine reservoirs for fecal bacteria and phytoplankton

Polyethylene terephthalate (PET) is frequently used in the food and beverage industry and therefore contributes greatly to plastic marine debris. The fecal pollution indicator bacteria Enterococcus is used for marine water contamination assessments and is regularly found in storm water discharge. In order to examine if PET drinking bottles act as refuges for Enterococcus, a study was conducted within euhaline tidal waters of Wrightsville Beach, NC, USA via the deployment of bottle floats positioned nearby two stormwater outfall pipes. Bottles were retrieved weekly to assess the accumulation of fecal bacteria and phytoplankton. Each bottle was analyzed for the presence of Enterococcus on plastic surfaces and within water inside the bottle. Abundance of Enterococcus and planktonic chlorophyll α was found to be significantly greater in association with PET bottles versus the surrounding waters. Bottles were observed to act as reservoirs for both Enterococcus and phytoplankton with concentrations well above the state, federal, and WHO standards. [Display omitted] •Enterococcus grows on plastic surfaces and within water contained by plastic drinking bottles.•Polyethylene terephthalate absorbs UVB radiation providing a unique refuge for Enterococcus.•Polyethylene terephthalate-associated Enterococcus is significantly greater than in seawater.•Chlorophyll α concentrations are significantly greater in plastic contained water vs seawater.•Polyethylene terephthalate bottles act as a microenvironment supporting microbial growth.