Biobased plastics have experienced fast growth in the past decade thanks to the public concerns over the environment, climate change and the depletion of fossil fuels. This perspective provides an overview of the current global market of biobased plastics, their material properties, technical substitution potential and future market (for 2020). In addition, the technology and market development of three biobased plastics, namely polylactide (PLA), biobased polyethylene (PE) and biobased epoxy resin, are discussed in detail. The emerging biobased plastics market is still small compared to traditional biobased polymers and biomaterials. The global capacity of the emerging biobased plastics was only 0.36 million tonnes in 2007. However, the market grew strongly between 2003 and 2007 (approx. 40% per year). The technical substitution potential of biobased plastics replacing petrochemical plastics is estimated at 90%, demonstrating the enormous potential of biobased plastics. Global capacity of biobased plastics is expected to reach 3.45 million metric tonnes in 2020. Starch plastics, PLA, biobased PE, polyhydroxyalkanoates (PHA) and biobased epoxy resin are expected to be the major types of biobased plastics in the future
Freshwater capture fisheries are globally essential for food security and aquatic biodiversity conservation. The Yangtze River Basin is the third longest and one of the most human-influenced drainage basins worldwide. Since the founding of P. R.China in 1949, this large river system has suffered increasing human perturbation and its sustainable development is now severely challenged. Meta-analysis showed that Yangtze River fisheries have experienced an extraordinary process of utilization-over-exploitation-protection during the past 70 years, to an extent that other globally important rivers may never have encountered. Its fisheries appear to have collapsed over the past four decades, with yield decreasing to only 25% of an historical peak of 400,000 metric tonnes in the late 1950s. Endemic, migratory and rare fishes have been highly threatened with obvious changes in fish community structure and aquatic biodiversity. Anthropogenic activities, including impoundment of water in dams, discharge of pollutants and riverine modification for vessel navigation, have caused large decreases in fisheries yields. Projections from surplus production modelling showed potential for improvement under fishing ban scenarios, but without any prospect for full recovery to historical stock status. This study revealed that the change in fisheries resources was dominated by the social-ecological watershed system, and an integrated approach to river basin management is warranted. Better management of freshwater ecosystems to integrate food security with biodiversity conservation is urgently needed throughout the world, and the changes evident in the Yangtze River fish populations can serve as an informative global reference.
K E Y W O R D Sbiodiversity conservation, China, fishing ban, food security, human impact, inland fishery
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