I arranged my visit through Christy Tyler and Mathew Hoffman, an ecologist and a mathematician respectively. Christy had just returned from a scouting trip to San Salvadore in the Bahamas. There’s an old naval base there, that is now a facility (Gerace Research Center) for researchers to use and collaborate with each other and with the Bahamians. On this small remote island, “plastics were everywhere” said Christy, who is now thinking of a long-term microplastics study there. One idea is to look at the extent to which the aspect, or direction of the beach determines the types and amounts of microplastics that wash up. This has been done in the Galapagos by Jones et al. (Sci. Total Environ. 2021). Another idea is to apply hyperspectral imaging to beach microplastics. This new type of imaging from airplanes can identify individual trees in the Amazon. Maybe it could be used to identify plastics on the beach? Perhaps we can both bring students down there and work together on one of these ideas?
Christy and Matt (and others) are about to be part of a giant, holistic microplastics project with Canadian counterparts in the Experimental Lakes Area. The idea is to dose a whole lake with microplastics of known type, shape and quantity, and them measure where they go, what critters take them in, and what happens to them when they do. You can read more about this project here. Over the years, we have learned a lot by studies done at the Experimental Lakes area, on nutrient loading, mercury, and endocrine disruptors; it is nice to see that microplastics are getting their turn. But wow, that’s big level stuff.
Less glamorous, but more accessible, is the RIT project to examine the plastics and other trash in the rural-urban gradient of the Rochester area. To do this, they installed Littatraps at several locations, similar to a study done by Japanese. These traps are installed under the stormwater grates and collect whatever falls in. It turns out, A LOT of stuff falls down there: cigarette buts, chip wrappers and hypodermic needles, and even a stray hot dog. That means the project’s goal of documenting every macro-trash item and a subset of the microplastics has turned into a huge undertaking, and bins are backed up for ant and fly removal and drying before they move onto the next phase of the process.
Another member of the RIT team is Nathan Eddingsaas. He is the chemist on the team, and is working on methods development, specifically for sediment. It’s tough to separate microplastics from sediment, as one needs to find a liquid that is lighter than sediment and heavier than microplastics but doesn’t breakdown the microplastics. Nathan prefers potassium carbonate, with a density of about 1.5, and little effect on microplastics. He does this twice, once before and once after an oxidative digestions step. He likes to filter his samples onto aluminum screens, which he says “you can buy for a fortune from a research supplier, or you can go to NAPA Auto Parts and buy a sheet of aluminum and cut them out yourself.” Nathan also showed me is FTIR and Raman set ups. Using the reflectance of microplastics with FTIR, he finds that the libraries of signatures online do not cut it – and he has made his own library specific to his machine.
It so happened that my visit coincided with the group’s weekly meeting, so I was able to meet with the rest of the research team, including Steven Day, André Hudson, and a whole team of research students. Wow, such an interdisciplinary, hard-working group! I can’t wait to hear the results of their current work (and maybe work together in the Bahamas!)