Plastic Exposure:
Who, What, Where,
So What?
Marine plastic debris is recognized as a pollutant of international concern due to impacts on wildlife and seafood safety. The ubiquity of marine plastic debris has created a monumental environmental pollution problem with extensive public health consequences, as more people move to coastal areas. Microplastic ingestion can lead to negative health consequences, and they can leach harmful chemicals (e.g., phthalate plasticizers) that can disrupt hormone activity. As apex predators with a long lifespan (>60 years), bottlenose dolphins can serve as sensitive gauges to detect disturbances in their local environment. As such, they can help us learn about the extent of environmental contamination due to plastic pollution.
Why We Do What We Do
Characterizing Plasticizer Exposure
Our recent studies detected prevalent phthalate exposure among free-ranging bottlenose dolphins in Sarasota Bay, FL (~75%; n=51; 2010-2019; Hart et al., 2020; Dziobak et al., 2021), which is located in one of the fastest growing metropolitan regions in the United States. Our studies demonstrated no significant differences in phthalate exposure between male and female dolphins or between juveniles and adults, which suggests that all Sarasota Bay dolphins may be at risk of exposure . The most commonly detected metabolites were monoethyl phthalate (MEP), and mono-(2-ethylhexyl) phthalate (MEHP), which are metabolites of parent compounds commonly added to personal care products and plastic. In fact, Sarasota Bay bottlenose dolphins had significantly higher concentrations of MEHP, the metabolite of di-(2-ethylhexyl) phthalate (DEHP), than human reference populations. While the source of phthalate exposure is uncertain for these dolphins, our findings suggest a plastic origin.
Watch What You Eat
Although exposure to phthalates is prevalent among bottlenose dolphins in Sarasota Bay, FL , the sources of exposure are unknown. We hypothesize that dolphins are exposed to these endocrine-disrupting chemicals via microplastic-contaminated fish. Further, we suspect that vulnerability to exposure varies geospatially, given differences in factors that impact microplastic abundance and distribution (e.g., urbanization, coastal hydrology, stormwater/effluent management, land use). We are currently conducting studies to quantify and characterize phthalate exposure in common prey fish for Sarasota Bay bottlenose dolphins. We are also exploring linkages between ingested microplastics and phthalate exposure, as well as spatiotemporal differences in exposure. Because fish are a shared resource between dolphins and humans, these investigations may help predict exposure risks for coastal communities. Furthermore, findings from this research will assist with efforts to monitor seafood contamination and help to inform intervention and risk communication needs regarding seafood safety.
Follow Us on Instagram
for Lab Updates!
@hoperesearchlab
