Marine Litter: Are There Solutions to This Environmental Challenge?

Abstract

Between 1950 and 2015, it is estimated that 6300 Mt of plastic waste have been produced. Of this, around the 80% ended up in landfills or in the natural environment [1]. The combination of this type of waste disposal and of the durability and resistance to degradation of plastics, has led to the current ubiquitous and abundant presence of plastic debris in the environment. The greatest warning signal of this plastic pollution problems has come from marine environment, where it is estimated that 75% of all marine litter is plastic and this debris has been reported to be accumulating at the sea surface [2], on shorelines of the most remote islands [3], in the deep sea [4] and in arctic sea ice [5]. Despite first reports on marine plastic litter dates back to the 1960s (Kenyon & Kridler, 1969) only recently it has been recognized as a pervasive global issue [1]. There is a range of evidence on the harm caused by marine litter; with negative impacts on commercial fisheries, maritime industries and infrastructures, as well as on a wide range of marine organisms as a consequence of entanglement and ingestion [6]. Plastic debris can be defined and described according to different characteristics including origin, polymer type, shape, size, colour or original use. However, the main classification used is about the size: macroplastic (>20 mm diameter), mesoplastic (5–20 mm) and microplastic (<5 mm) [7]. Since macroplastics are more visible, they have been for long time considered as one of the most concerning forms of plastic pollution. In fact, these items can be more easily recognized and categorised according to their original usage (i.e. fishing, packaging, or sewage related debris). More subtle and complicate is instead the pollution related to the presence of microplastics that, with accumulating data on the impact and consequences of such debris, has received increasing research interest and currently represents one of the greatest challenges in the fight against plastic pollution