New research suggests dolphins in captivity may be exposed to more microplastics than their wild counterparts – a startling discovery that highlights how deep plastic pollution seeps even in controlled environments.
What is going on?
A study, published in the journal Communications Earth & Environment, aimed to identify microplastics — tiny particles that result from the degradation of plastic — in the tissues of captive and wild lemurs, including the skin, lungs, liver and intestines.
The researchers said this was an important distinction, as many previous studies focused only on microplastics in the gut contents. The scientists hoped to determine if the microplastic contamination extends into the tissue.
Microplastics were found in 80% to 100% of all tissue samples from both wild and captive dolphins, confirming that microplastics penetrate the entire body rather than being confined to the digestive system.
Perhaps most surprisingly, captive dolphins carried much higher microplastic loads than wild dolphins.
Captive animals averaged 0.67 microplastics per gram of tissue compared to 0.19 microplastics per gram in wild dolphins.
Wild dolphins showed a wider variety of microplastic shapes and colors, which scientists attributed to diverse environmental sources. Kept dolphins showed more uniform types, likely linked to indoor or aquarium-related materials such as textile fibers, facility equipment, or contaminated food and water.
Polyamide and PET were the most common types of plastic found overall. Polyamide, more commonly known as nylon, is often found in textiles, rope, and industrial and auto equipment.
PET, or polyethylene terephthalate, is often found in plastic bottles, food packaging, and polyester clothing.
Why are these findings important?
Research on microplastics is still emerging, and scientists are just beginning to understand the full impact of these tiny particles. What is clear, however, is that they are incredibly widespread and can cause lasting damage.
“Microplastics… are increasingly recognized as a threat to marine ecosystems,” the study observed.
The research highlights how much plastic pollution can infiltrate living organisms — and how even captive species are not protected from exposure. The higher microplastic loads found in captive dolphins show that plastic contamination extends well beyond our polluted oceans.
Plastics are woven into everyday life – found in textiles, buildings, food packaging, and more. As they degrade, microscopic plastic particles filter into the environment, infiltrating our food, water, and even the air we breathe.
With such a high presence of microplastics in both wild and captive dolphin tissue, the study raises serious questions about what loads of microplastics other marine species – and even humans – may be carrying.
With microplastic pollution linked to health impacts such as cancer, lung problems, hormone disruption, and more, the stakes are high for all living things.
What is being done about microplastics in marine life?
Microplastics research is still developing – and has room for improvement. The experts called for more attention to animal tissues in microplastic research, emphasizing that the analysis of gut contents alone significantly underestimates microplastic toxicity.
They advocate monitoring various tissues to better understand exposure levels and assess potential health risks to both wildlife and humans.
To help address the impact of plastic pollution on marine life, efforts have historically focused on cleaning up the plastic waste already in our oceans. Attention from governments, conservation groups, and industries has grown to reduce the amount of plastic produced.
Developing alternatives to plastic and restricting the use of certain plastics — such as microbeads in cosmetics or single-use plastic bags — are key steps towards reducing pollution. There is also a need to improve recycling and waste management systems, which can prevent plastic from entering waterways in the first place.
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