dolphin, animal, mammal

Wild Dolphins Found with Microplastics in Their Breath A New Study Reveals

In a groundbreaking study published in PLOS One, scientists have uncovered the presence of microplastics in the exhaled breath of wild bottlenose dolphins off the southeastern coast of the United States. This research marks the first evidence that marine mammals may inhale these harmful particles, raising concerns about their potential health effects.

Understanding Microplastics

Microplastics are defined as plastic fragments smaller than 5 millimeters (less than one-fifth of an inch) and have been increasingly linked to negative health impacts in both humans and wildlife. Previous studies have shown these tiny particles in marine mammals’ tissues, primarily through ingestion. However, this new research opens the door to inhalation as a significant exposure route.

The Study’s Findings

The study focused on 11 wild bottlenose dolphins, with samples taken from six dolphins in Louisiana’s Barataria Bay and five from Sarasota Bay in Florida during health assessments in May and June 2023. Researchers collected breath samples by holding petri dishes to the dolphins’ blowholes. Under microscopic examination, each dolphin was found to have exhaled at least one microplastic particle, with polyester—commonly found in clothing—being the most prevalent type.

Co-lead author Miranda Dziobak, an environmental scientist at the College of Charleston, remarked, “We found that dolphins may be breathing in microplastics, even if they live in rural areas away from high levels of human activity. This demonstrates that these particles are everywhere, regardless of urbanization and human development.”

Implications for Marine Mammals and Humans

The inhalation of microplastics could pose serious risks to dolphin lung health, although the specific effects are still unclear. The authors expressed disappointment yet acknowledged the inevitability of plastic contamination in wildlife, noting that “plastics have contaminated virtually every part of the globe.”

Greg Merrill, a doctoral student at Duke University and co-author of previous studies on marine mammal microplastic exposure, emphasized the broader implications: “Confirmation that cetaceans inhale microplastics as well as consume them means that our estimates of total microplastic exposure to these species are underestimated.”

Broader Environmental Context

The researchers noted that microplastics can be propelled into the atmosphere through ocean wave activity, which means other marine mammals that surface for air could also be exposed. While this study concentrated on dolphins, the implications extend to other marine and terrestrial mammals.

Future Research Directions

Dziobak and her team plan to continue their research on microplastic inhalation in dolphins to better understand the specific types of plastic they encounter and the potential health risks associated with them. Given that bottlenose dolphins can live for at least 40 years and often remain in the same habitats, monitoring their health could provide valuable insights into environmental changes that might also affect human populations.

Merrill pointed out the shared physiology between humans and marine mammals, highlighting the potential risks for human health due to the contamination of shared marine ecosystems. “We share much of our physiology with marine mammals and consume much of the seafood they eat, so this research has considerable implications for human health,” he said.

The detection of microplastics in the breath of dolphins underscores the pervasive nature of plastic pollution in our oceans. As research continues to uncover the myriad ways these materials affect marine life, it serves as a stark reminder of the need for concerted efforts to combat plastic pollution and protect our oceans for both wildlife and human health.