Did you know that the plastic we throw out has created a completely new ocean habitat? It’s called the Plastisphere, a term coined by Prof. Dr. Linda Amaral-Zettler, a research leader at the Royal Netherlands Institute for Sea Research (NIOZ) and Chair in Marine Microbiology at the University of Amsterdam to refer to the community of microbes that live on plastic.
Everything that floats in the ocean, including plastic, attracts tiny microbes. However, the microbes that live on plastic can be very different from those found in the surrounding seawater. In seawater, certain types of microbes tend to dominate followed by a long list of rarer organisms. The pattern is very different on plastics. The plastisphere microbial community is highly diverse but contains only a few representatives of each microbial group, including some that aren’t usually found in seawater.
Because plastic doesn’t break down quickly in seawater, the microbes that live in the plastisphere can end up being transported long distances into new environments where they could impact the native communities. Linda’s research focuses on what determines the makeup of the community of microbes that live on plastic and why the community stays so diverse. “Being a microbial ecologist you can start talking about bacteria and people’s eyes kind of glaze over, but then you start talking about plastic and people get really emotional,” she says. “They can relate to plastic. Everyone can relate to plastic!”
Access to the sea is crucial for Linda to conduct her research. Fortunately for her, NIOZ has its own fleet of three research vessels. “The vessels are a huge resource that shouldn’t be overlooked or taken for granted,” she says. Since coming to NIOZ two years ago, Linda has led three research cruises on NIOZ's open-ocean research vessel the Pelagia to collect samples for her plastisphere research. Last summer, Linda and 11 other scientists travelled from the Azores to Sicily to collect samples of microplastics, and this past January she spent three weeks collecting samples from what’s called the South Atlantic "Garbage Patch". This gigantic pile of garbage was created over decades by the large system of circulating ocean currents and it’s chock full of the microbes that Linda studies. Setting off from Cape Town, Linda and her colleagues took samples of the plastic from not only the surface of the garbage vortex but also at depth and on the ocean bottom.
Linda has also started to explore what happens to biodegradable and compostable plastics that end up in the oceans. “A lot of people hear the word biodegradable and assume that means biodegradable everywhere. That’s anything but true. We’re trying to better understand how biodegradable plastics behave in the marine environment, which is not where they’re meant to biodegrade,” she explains.
In addition to the fleet, Linda has another strong resource for her research in her NIOZ colleagues. “At NIOZ I’m part of a marine microbiology department which is pretty cool. There aren’t that many of those out there. It’s nice to have so many like-minded colleagues,” she says. She enjoys how the academic culture of the Netherlands is less independent and individualistic than the United States, where she worked previously. “Here collaboration is celebrated, which is a breath of fresh air,” she added.
Linda also finds that Europe has higher scientific awareness of the problems created by plastics which has helped her make connections with new collaborators. She has been able to publish some of the studies she’s been working on and secure funding for new projects and new students. “I’m educating the next generation of scientists on some of these problems that, unfortunately, look like they’re here to stay,” she says. “It’s a good time in my career to be here.”
Prof. Dr. Linda Amaral-Zettler is a Research Leader in the Department of Marine Microbiology and Biogeochemistry at the Royal Netherlands Institute for Sea Research (NIOZ). Linda also holds a Special Chair in Marine Microbiology at the University of Amsterdam and is a Fellow at the Marine Biological Laboratory and an Adjunct Professor at Brown University.