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Globally, there is rising awareness of the severity of the plastic waste problem, and the implications of plastics accumulation in the environment. Current methods of waste management are anticipated to be insufficient in mitigating the long-term negative impact on society and the environment. Plastics recycling is one of many solutions that have been proposed, one of the most ecologically-friendly, as well as holding great economic potential by its realization into a circular economy. The technological know-how already exists for a number of different methods for plastic recycling; however, they are broadly uneven in their implementation due to feasibility and cost issues. Here, we review and compare methods of tertiary recycling—that is, complete breakdown of plastics into its chemical component materials—and offer an analysis of the potential obstacles that have to be addressed to increase waste plastic recycling rates. While chemical recycling methods are simpler and are already pilot tested at an industrial level, biological recycling either via microorganisms or biological-derived enzymes are as yet unproven but highly promising technologies. Looking forward, trend shifts towards more ecologically-friendly processes will drive initiatives to close the loop on commercial plastic production.

The accumulation of plastic waste is a pressing environmental problem, growing hand-in-hand with the rising production and consumption of consumer products. The robustness and intrinsic strength of plastics, which render them extremely useful in various packaging applications, are a double-edged sword as they are likewise highly resistant to degradation and may persist for several millennia. Conventional waste treatment solutions are increasingly unable to manage the growing volume of such waste, bringing us to the brink of ecological disaster. Interestingly, environmental microorganisms are beginning to evolve their own biological means of thriving within such environments through production of metabolic intermediaries that enable them to utilize plastics as energy sources. Here, we present a brief review of the current literature, highlighting various micro- and multicellular organisms that have been found to degrade plastics, as well as propose some strategies for industrialization of these processes in the future.

Species invasion is an important cause of global biodiversity decline and is often mediated by shifts in environmental conditions such as climate change. To investigate this relationship, a mechanistic Dynamic Energy Budget model (DEB) approach was used to predict how climate change may affect spread of the invasive mussel Mytilopsis sallei, by predicting variation in the total reproductive output of the mussel under different scenarios. To achieve this, the DEB model was forced with present-day satellite data of sea surface temperature (SST) and chlorophyll-a concentration (Chl-a), and SST under two warming RCP scenarios and decreasing current Chl-a levels, to predict future responses. Under both warming scenarios, the DEB model predicted the reproductive output of M. sallei would enhance range extension of the mussel, especially in regions south of the Yangtze River when future declines in Chl-a were reduced by less than 10%, whereas egg production was inhibited when Chl-a decreased by 20-30%. The decrease in SST in the Yangtze River may, however, be a natural barrier to the northward expansion of M. sallei, with colder temperatures resulting in a strong decrease in egg production. Although the invasion path of M. sallei may be inhibited northwards by the Yangtze River, larger geographic regions south of the Yangtze River run the risk of invasion, with subsequent negative impacts on aquaculture through competition for food with farmed bivalves and damaging aquaculture facilities. Using a DEB model approach to characterise the life history traits of M. sallei, therefore, revealed the importance of food availability and temperature on the reproductive output of this mussel and allowed evaluation of the invasion risk for specific regions. DEB is, therefore, a powerful predictive tool for risk management of already established invasive populations and to identify regions with a high potential invasion risk.