INTO THE PLASTISPHERE

A unique synthetic ecosystem is evolving in our oceans – welcome to the plastisphere

- JOSEPH PHELAN

CONSIDER A PLASTIC BOTTLE BOBBING on the ocean's surface, thousands of miles from the nearest coastline. To the naked eye, it appears lifeless – just another piece of discarded waste adrift on an endless sea.

But, peer closer, and this fragment of human negligence reveals itself as a thriving metropolis. Bacteria cluster in dense colonies across its weathered surface. Algae paint it green with photosynthetic films. Tiny invertebrates graze on the microbial lawns, while goose barnacles cement themselves to its edges.

Welcome to the plastisphere, an entirely new ecosystem born from our refuse.

The term, coined by marine microbiologist Linda Amaral-Zettler more than a decade ago, describes the unique communities of life that colonise plastic debris in our oceans. It’s a concept that challenges our understanding of both pollution and resilience, revealing how life doesn't simply suffer from our environmental mistakes but adapts to them in ways we're only beginning to comprehend.

“What has surprised us most is the diversity of species present on such small fragments of plastic,” says Amaral-Zettler, who has been studying these communities at the Netherlands Institute for Sea Research since their discovery.

Each colonised piece of plastic, she found, hosted its own distinct microbial neighbourhood, even when collected from the same location. Life wasn't just surviving our waste - it was making it home.

To understand how plastic becomes an ecosystem, we must appreciate what makes it different from anything nature has produced. When a piece of driftwood enters the ocean, for example, marine organisms may colonise its surface. But, within months, that wood will decompose, causing its passengers to perish. Plastic is a very different proposition.