Very first up is a visit to Dr. Javier Lloret! This Spaniard has been studying and modelling estuaries and wetlands for a long time, and recently along Cape Cod. One of his publications that I came across looks at how salt marsh sediments accumulate microplastics over time.
With no one around, it was pretty easy for Javier and I to recognize each other. We spent an hour chatting in his office; and the parallel threads of our experiences and interests joined and separated and joined again. Javier is a self-described “slash” scientist: aquatic ecologist/ecosystem specialist/biogeochemical cyclist. But never a modeler. He is interested in the big global picture, but sees the local environment as a way to scale up to the planet. Pollution, he says, is one of his playgrounds; not really central to his main focus, but where he likes to have fun.
Javier is either lazy or smart; he says he is lazy because he likes nature to do his collecting and concentrating for him. But that’s what makes him smart. Pushed by his summer Semester in Environmental Science students, Javier took on his first microplastics project. He opted to use his collection techniques for nitrogen studies – collecting sediment cores from the salt marsh so he could reconstruct a MP depositional history and compare different areas. Salt marshes are areas of high deposition that is not very disturbed because the sediment is “sticky”. The collection was the easy part; the analysis “was a nightmare”. I can relate. His first problem was the self-contamination – where nylon and other fibers from his shirts or those of his students ended up in the samples. Who was wearing blue on Tuesday? More strict and more successful protocols were implemented, but it was almost too burdening. Javier and his team found that fragments seem to better reflect patterns of human development, whereas fibers are universally distributed. Those MP fibers are everywhere; I have found the same – in our air, rain, snow and waters. Javier says this first sediment microplastic work taught him that he didn’t want to do it again because the protocol was “too painful”. I can relate. Many of us use separatory funnels to density separate sediments from microplastics, but Javier’s sediment “cookies” (a round slice from the sediment core) required too large a volume of ZnCl solution to fit in the largest separatory funnel. So, he had a colleague with some engineering (or plumbing) chops build a more robust apparatus that was used by researchers elsewhere (see below). This apparatus sits in Javier’s office because it proved useless, the valve clogged instantly and could not be cleaned out. But it is not useless, it is a reminder that failures happen and make for good stories.
Javier then explored another area of his plastic playground - the effects. It is what people are ultimately most interested in, and we don’t yet have very clear answers. “I don’t know if the ecosystem is being affected,” Javier admitted. He is working on another project, using the ubiquitous ribbed mussels of the salt marsh to accumulate the microplastics for him. It turns out that the mussels do accumulate microplastics for sure, with higher numbers of microplastics closer to human development, just like the sediment. What is less clear is whether this affects the mussels. High-level acute exposure doesn’t seem to cause too much stress to the mussels, at least not enough to change their respiratory rates. What would happen during chronic exposure, over the 5–6-year lifespan of a mussel, is untested and unknown. Not many people are interested in long-term work with mussels in the lab: Javier was almost expelled from one lab when he proposed digesting mussel tissue. There isn’t much that creates a worst stink than decaying mussel tissue. I can relate. We tried looking at microplastics in zebra mussels. I was likewise almost evicted from the Center for Natural Sciences.
With an interest in the global scale, Javier wants to look for microplastics in a remote place – the Arctic, and Toolik Lake in Alaska specifically. Funny, I have been to Toolik Lake looking for pollutants myself. I can relate. Thank you Javier!
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