Plastic is virtually everywhere on Earth. From the tallest mountain to the deepest ocean, from the polar regions to inside our bodies — there’s no escaping it anymore. Although plastic pollution is far from a new problem, the sheer extent of microplastic pollution has only recently come into the spotlight.

Plastic pollution is typically split into larger macroplastics (>5 cm), microplastics (0.1 µm—5 mm) and nanoplastics (<0.1 µm). The smaller the plastic, vaster the distances it travels from its source. This means that small plastic pieces are far more pervasive than bigger ones. And it’s these small pieces that are more likely to be ingested by animals.

We’ve seen the striking photos of birds ingesting plastic pieces and suffering from this, but the smaller pieces are harder to spot — that’s why they went undiscovered for so long. But small pieces of plastic can also accumulate over time, and the damage that they do is harder to assess.

Finding small plastic

With this in mind, PhD researcher Davide Taurozzi and Professor Massimiliano Scalici, of Roma Tre University, Italy, embarked on a project to summarize 40 years of research into seabird ingestion of microplastics. They analyzed data starting in 1983 and coming to the present day. It was a “study of studies” that put together a collection of bird sample data recorded over this period.

Overall, they gathered the data of over 1,100 samples including excrement, regurgitation, and food from crop pouches that some birds use to temporarily store food. Most of the samples were pellets. They found clear evidence that 13 species of polar sea birds (both around the Arctic and the Antarctic) had consumed microplastics. Species like little auks, king penguins, great shearwaters, and Adelie Penguins all showed traces of ingested microplastics. It wasn’t just a few individuals, either — the vast majority of birds had plastics inside them.

A whopping 97% of Antarctic birds had plastic inside them, as did 90% of the Arctic birds. An average of 7.2 and 1.1 plastic pieces were found in the Antarctic and Arctic birds, respectively. However, some birds had way more pieces than that. The median numbers [[difference average median]] of plastic pieces was 31.5 and 35 respectively.

It wasn’t just one piece of plastic, either. The team discovered 14 types of plastics inside birds. The most common one was polyethylene, a plastic commonly used in plastic bags, containers, bottles, and packaging materials. Polypropylene and polystyrene, two plastics used in things like textiles, automotive parts, and reusable containers, were also common.

Another problem for the polar areas

Birds in polar areas are in big trouble. There are 64 and 43 species inhabiting the Arctic and Antarctic respectively, but their numbers have been steadily declining over the years, due to stressors such as climate change and pollution. Plastic is yet another problem, and it’s even more troublesome in the polar areas, where the landscape is relatively pristine and there is less pollution. But the “pristine” status of polar areas is dwindling every year.

Commercial fishing and maritime routes are becoming more frequent, and climate change continues to take a toll. These further exacerbate the vulnerability of these ecosystems to plastic pollution. The intrusion of plastic into such environments not only poses a direct threat to wildlife through ingestion and entanglement but also acts as a carrier for other pollutants that adhere to its surfaces, introducing additional toxic substances into these fragile habitats. There is now an accumulation of challenges faced by polar species, many of which are already endangered or threatened species.

This is why the work of researchers like Taurozzi and Scalici is invaluable. It highlights the urgent need for global action to reduce plastic production and improve waste management practices. The Arctic covers around 6% of Earth’s surface and is still comparatively pristine, but the implications of human encroachment on the natural world here can be devastating.

Ultimately, protecting the polar regions and their inhabitants requires concerted efforts from individuals, industries, and governments worldwide, united in the commitment to preserving these vital parts of our planet for future generations.

Journal Reference: Davide Taurozzi et al, Seabirds from the poles: microplastics pollution sentinels, Frontiers in Marine Science (2024). DOI: 10.3389/fmars.2024.1343617