Can Pollution Cause Growth?

   It is predicted that plastic waste entering our oceans will increase ten-fold within the next decade, however the leaching effect plastics have is often hard to quantify due to its lack of physical appearance. Romera-Castillo et al. (2018) use lab-cultured experiments to measure the potential impacts of dissolved organic carbon (DOC) leached by plastic on marine microbial life.

   

   On the surface microlayer of the sea, photodegradation of plastics produces free radicals which potentially inhibit bacterial growth. Treatments exposed to artificial solar radiation produced a low bacterial abundance, suggesting that the DOC products are not utilizable by marine microbes. However, the inverse was true for treatments left in the dark, implying that plastic-derived DOC could enhance microbial growth well below the ocean’s surface. Most plastic is found below the surface of the ocean, which could surprisingly lead to hot spots of microbial activity because of DOC.

   

   This study, whilst only representative of the leachates produced by polyethylene and polypropylene, produced results that can be significant to our understanding of the ever-lasting impacts of plastic pollution. With the need to reduce plastic usage at an all-time high, studies like this can aid in the protection and rescue of our oceans.

Romera-Castillo, C., Pinto, M., Langer, T. M., Álvarez-Salgado, X. A., & Herndl, G. J. (2018). Dissolved organic carbon leaching from plastics stimulates microbial activity in the ocean. Nature communications, 9(1), 1430.