Estimation and prediction of plastic waste annual input into the sea from China BAI Mengyu 1 , ZHU Lixin 1 , AN Lihui 2 , PENG Guyu 1 , LI Daoji 1 * 1 State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China 2 State Environmental Protection Key Laboratory of Estuarine and Coastal Research, Chinese Research Academy of Environmental Sciences, Beijing 100012, China Received 23 August 2018; accepted 12 October 2018 © Chinese Society for Oceanography and Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Marine plastic debris has been a pervasive issue since the last century, and research on its sources and fates plays a vital role in the establishment of mitigation measures. However, data on the quantity of plastic waste that enters the sea on a certain timescale remain largely unavailable in China. Here, we established a model using material flow analysis method based on life cycle assessment to follow plastic product from primary plastic to plastic waste with statistical data and monitoring data from accurate sources. This model can be used to estimate and forecast the annual input of plastic waste into the sea from China until 2020. In 2011, 0.547 3–0.751 5 million tons of plastic waste entered the seas in China, with a growth rate of 4.55% per year until 2017. And the amount will decrease to 0.257 1 to 0.353 1 million tons in 2020 under the influence of governmental management. The amount of plastic waste discharged from coastal areas calculated in this study was much larger than that from river, thus it is suggested to strengthen the governance and control of plastic waste in coastal fishery activities in China in order to reduce the amount of marine plastic waste input. Key words: plastic waste, prediction, China, marine, material flow analysis Citation: Bai Mengyu, Zhu Lixin, An Lihui, Peng Guyu, Li Daoji. 2018. Estimation and prediction of plastic waste annual input into the sea from China. Acta Oceanologica Sinica, 37(11): 26–39, doi: 10.1007/s13131-018-1279-0 1  Introduction After the first piece of plastic debris was discovered in the sea in the early 1970s (Carpenter and Smith, 1972; Fowler, 1987; Colton et al., 1974), plastic has been pervasive in all habitat types worldwide due to its durability, low density and universal use (Derraik, 2002). Plastic debris has appeared in gulfs (Hinojosa and Thiel, 2009), bays (Ryan, 2013), and lakes (Free et al., 2014), on the shores of the remotest islands (Barnes, 2005; Morishige et al., 2007), in polar waters (Barnes et al., 2010; Bergmann and Klages, 2012), and in high concentrations in the Great Pacific Garbage Patch (Lebreton et al., 2018). Marine plastic debris and microplastics may affect the survival of marine organisms. They may threaten the health of marine organisms by causing entan- glement (Derraik, 2002; Gregory, 2009), destroying habitats (Donohue et al., 2001; Barnes, 2002), and choking and starving wildlife (Wright et al., 2013) etc. The United Nations Environ- ment Assembly (UNEA) classified marine plastic debris and mi- croplastics as one of several environmental issues of particular concern in 2016. Plastic debris can enter the sea by three ways: direct littering to rivers, beaches and the seas (Lebreton et al., 2017); dispersal by water and wind (Kershaw and Rochman, 2015); and losses during transport or by accident (Barnes et al., 2009). Quantitative research on the sources and fates of marine plastic debris plays a very important guiding role in mitigating and minimizing the ef- fects of marine plastic debris on the environment. Eriksen et al. (2014) calculated the quantity of macroplastics and micro- plastics using a modeling approach and concluded that the amo- unt of plastic debris in the North Pacific is 0.096 4 million tons (Mt), while the amount in the South Pacific is 0.021 0 Mt. Jam- beck et al. (2015) estimated that in 2010, 1.32–3.53 Mt of misman- aged plastic waste was input from land into the sea in China. Meanwhile, rivers are a major transport pathway for plastic waste from land to sea. After summing the inputs from the 5 rivers in China, Schmidt et al. (2017) concluded that the annual load of macroplastic input from China into the sea was 0.094 5 Mt. Lebreton et al. (2017) estimated the aggregate annual macro- and microplastic input from the Xijiang and Dongjiang Rivers, which flow into the Zhujiang River Delta and Changjiang River, to be 0.436 Mt. To investigate the temporal trends of plastic garbage entering the sea in China over a ten-year time period, in this study, a mod- el was first established based on the material flow analysis meth- od. Material flow analysis (MFA) is a systematic assessment tool used to determine the flows and stocks of materials within a sys- tem defined in space and time (Van Eygen et al., 2017). The main components of an MFA model include the sources, pathways, in- termediates and final sinks of a material. All inputs, stocks, and outputs of a material within the model are balanced according to the law of conservation of mass (Brunner and Rechberger, 2004). This study connected processes ranging from the production of primary plastic to the discharge of plastic waste into sea in China using the flows of plastics, evaluated material inputs throughout the lifecycles of plastic products, and finally, estimated and pre-   Foundation item: The National Key Research and Development Program of China under contract No. 2016YFC1402200; the National Natural Science Foundation of China under contract No. 41676190. *Corresponding author, E-mail: daojili@sklec.ecnu.edu.cn   Acta Oceanol. Sin., 2018, Vol. 37, No. 11, P. 26–39 DOI: 10.1007/s13131-018-1279-0 http://www.hyxb.org.cn E-mail: hyxbe@263.net