Disposable surgical masks affect the decomposition of Zostera muelleri.

The coronavirus pandemic has caused a surge in the use of both disposable and re-usable mask pollution globally. It is important to understand the potential impact this influx of novel pollution has on key ecological processes, such as detrital dynamics. We aimed to understand the impact mask pollution has on the decomposition of a common coastal seagrass, Zostera muelleri. Using an outdoor mesocosm system with heater chiller units and a gas mixer, we were able to test the impact of both re-usable single-ply homemade cotton masks and disposable surgical masks on samples of Z. muelleri detritus under different environmental conditions. We found that disposable masks, but not re-usable masks, significantly increased decomposition of Z. muelleri detritus. This may be due to the increased surface area available for detritivorous microorganism colonisation, driving further decomposition. This could have negative ramifications for seagrass communities and adjacent ecosystems.