Today, April 22nd 2024, marks the 54th anniversary of Earth Day! It is both a celebration of this incredible planet we call home, and a reminder that it needs our care and protection. The theme for this year brings attention to the Plastic Pollution Crisis, and the importance to push for the rapid phase-out of plastics globally. So on this day, coinciding with Hong Kong’s next stage of its disposable plastic phase-out, let us explore the entangled relationship between Plastics and Biodiversity through the story of four species, for a peek into the present, and a potential more hopeful future.
Our oceans have become sinks for plastic pollution globally, with an estimated 14 million tonnes of plastic entering marine waters each year. That’s about 1 garbage truck worth of plastic dumped every 3 seconds. Their effects on marine life is perhaps best exemplified by the Green Sea Turtle, 𝘊𝘩𝘦𝘭𝘰𝘯𝘪𝘢 𝘮𝘺𝘥𝘢𝘴, the only sea turtle species known to nest in Hong Kong. They help with maintaining healthy seagrass beds, controlling marine algal growth, and depositing nutrients to the sand dunes in which they lay their eggs. For this sea faring species, our islands are but a stop on a larger voyage that inevitably exposes them to our plastic debris. Ingestion and entanglement are primary concerns for these and other marine life that interact with discarded plastics.
Hong Kong is not just an important migratory stop for some marine species, but also for many seabirds flying along the East Asian – Australasian Flyway. The Common Tern, 𝘚𝘵𝘦𝘳𝘯𝘢 𝘩𝘪𝘳𝘶𝘯𝘥𝘰, is one of only 3 known seabird species that breed in Hong Kong, nesting in colonies on rocky inlets. Common Terns, like many other seabirds, travel between the open ocean, marshes, and onshore, playing an integral role in the movement of nutrients across vast distances. In recent years, concerning trends seen in local Common Terns have emerged in line with findings from other seabird species globally: the increased presence of plastic fragments in nest building and stomach contents. Thus sparking concerns over the survival of chicks, adults, and species reliant on the role which Common Terns and other seabirds fulfill.
The Yellow Mealworm, 𝘛𝘦𝘯𝘦𝘣𝘳𝘪𝘰 𝘮𝘰𝘭𝘪𝘵𝘰𝘳, likely originated from the Mediterranean region, although due to human trade and colonization, can now be found globally. Despite their name, they are not worms, but the larvae of the Flour Beetle. Within their gut is a secret weapon – bacteria that can digest and metabolize polystyrene, a plastic that cannot be recycled. Wax moths, 𝘎𝘢𝘭𝘭𝘦𝘳𝘪𝘢 𝘮𝘦𝘭𝘭𝘰𝘯𝘦𝘭𝘭𝘢, Superworms, 𝘡𝘰𝘱𝘩𝘰𝘣𝘢𝘴 𝘢𝘵𝘳𝘢𝘵𝘶𝘴, soil invertebrates such as the snail 𝘈𝘤𝘩𝘢𝘵𝘪𝘯𝘢 𝘧𝘶𝘭𝘪𝘤𝘢, and the earthworm 𝘓𝘶𝘮𝘣𝘳𝘪𝘤𝘶𝘴 𝘵𝘦𝘳𝘳𝘦𝘴𝘵𝘳𝘪𝘴, have also been discovered to have similar abilities. And while large-scale applications are still being developed, these invertebrates, some even perceived as pests or as insignificant, have given us an undeniable edge in tackling the difficult problem of plastic processing.
Pictured above is the algal species 𝘈𝘳𝘯𝘰𝘭𝘥𝘪𝘦𝘭𝘭𝘢 𝘴𝘪𝘯𝘦𝘯𝘴𝘪𝘴, discovered in China growing on the backs of freshwater turtles. Algae are an often overlooked group of organisms, yet have continued to yield incredible discoveries that have led to innovations in carbon sequestration, renewable energy production, and even plastic alternatives. Microalgae in particular have been successfully developed into bioplastics, a non-petroleum based plastic substitute. Other bioplastics already exist on the market made from corn, sugarcane, and tapioca, but these cash crop alternatives need large amounts of land, water, and nutrients, contributing to deforestation and water shortages. Algal bioplastics are much less energy and resource intensive, and can even be net carbon positive, thus helping with another problem: climate change.
It is worth noting that the innovations mentioned come from members of often overlooked groups of organisms. Recent studies have noted that insects, algae, and bacteria, have already begun to adapt to a world of plastics. Conservation efforts thus cannot only focus on protecting charismatic macrofauna, but holistic environments and all their organisms, including those underappreciated and understudied. So on this Earth Day, let us not be apathetic about the state of plastics globally, but appreciative of the human ingenuity and the incredible biodiversity that the Earth supports. For these may be the keys to unlocking a world beyond the Plastic Pollution Crisis.
All species mentioned in this article can be viewed at the Hong Kong Biodiversity Museum. So book a visit and check them out!