Dolphins Are Exhaling Microplastics

According to our recent research, which was published in the journal PLOS One, bottlenose dolphins in Sarasota Bay, Florida, and Barataria Bay, Louisiana, are emitting microplastic fibers.

Tiny plastic fragments have dispersed throughout the globe, including in the atmosphere, on land, and in the clouds. The oceans are believed to contain an estimated 170 trillion pieces of microplastic. On a global scale, research has shown that humans and wildlife are the main consumers and inhalers of microplastics.

Our research revealed that the chemical composition of microplastic particles exhaled by bottlenose dolphins (Tursiops truncatus) is comparable to that of those discovered in human lungs. It is uncertain whether dolphins are subjected to a greater amount of these pollutants than humans.

Why It Matters

In humans, inhaled microplastics can induce lung inflammation, which may result in tissue injury, excess mucus, pneumonia, bronchitis, scarring, and potentially cancer. Dolphins may be susceptible to the same respiratory complications as humans, as they inhale comparable plastic particulate.

Plastics are also found to contain compounds that can impact neurological function, cardiovascular health, and reproduction in humans, according to research. Microplastics may also have these health hazards for dolphins, as they are mammals.

Bottlenose dolphins, which have life spans of decades, are top predators that assist scientists in comprehending the effects of pollutants on marine ecosystems and the associated health hazards for individuals residing in coastal areas. This research is crucial due to the fact that over 41% of the global human population resides within 62 miles of a coastline.

What Isn’t Known

The oceans are believed to contain numerous trillions of plastic particles, which are transported there through runoff, effluent, or atmospheric sedimentation, according to scientists. These particles may be dispersed into the atmosphere by ocean surges.

In reality, the release of 100,000 metric tons of microplastics into the atmosphere each year is a consequence of bubble explosions that are induced by wave energy. Due to the fact that dolphins and other marine mammals breathe at the surface of the water, they may be particularly susceptible to exposure.

Plastic is typically more prevalent in areas with a higher population. However, this association is not always accurate for the minute plastic particles that are suspended in the air. Airborne microplastics are not restricted to densely populated areas; they also pollute undeveloped regions.

The breath of dolphins residing in both urban and rural estuaries was found to contain microplastics in our research. However, it is unclear whether there are significant differences in the quantities or varieties of plastic particles between the two habitats.

How We Do Our Work

Our study’s breath samples were taken from wild bottlenose dolphins during health examinations that were carried out in collaboration with the following institutions: Fundación Oceanogràfic, National Marine Mammal Foundation, Brookfield Zoo Chicago, and Sarasota Dolphin Research Program.

We took breath samples from the dolphins by placing a petri dish or a specialized spirometer, which assesses lung function, over their blowhole during these short-lived authorized health evaluations. We looked for microscopic plastic-looking particles in our coworker’s lab using a microscope. These could have smooth surfaces, vivid colors, or a fibrous form.

To determine if the pieces were indeed plastic, we heated them using a soldering needle, as plastic melts at high temperatures. Our colleague used Raman spectroscopy, a specialized technique, to confirm the materials’ plasticity. This technique employs a laser to generate a structural fingerprint that may be correlated with a particular chemical.

The scope of plastic pollution is brought to light in our study, along with the fact that dolphins and other living creatures are exposed to it. Reducing plastic consumption and striving to prevent more plastic from entering the oceans can help address the microplastic pollution problem, even though the implications of plastic inhalation on dolphins’ lungs are not yet established.