Marine biodegradability review of plastics

Abstract

Current test methods for estimating biodegradability and duration in the oceans, do not consider nitrogen as a limiting factor for bacterial growth and plastic biodegradation. Algae and cyanobacteria can thrive within widely ranging Nitrogen/Phosphorous ratios from 5:1 to 100:1 The ocean's biodiversity that we know could die off if algae and cyanobacteria out compete existing dominant bacteria. Normally organic loading would be localized, but the slow degradation of microplastics allows the circulation across all the oceans. Single use plastics, such as wipes are having an increasing impact due to significant growth of demand and particularly with sanitation concerns with COVID-19. Biodegradability of plastics needs to be reassessed and the use of actual ocean conditions is needed. Verifying claims of biodegradability need to be reassessed since these are based on methods that have not considered nitrogen limitations in the ocean.