Spatial and temporal distribution characteristics and source analysis of beach litter in Shandong province from 2009 to 2017

On the basis of the survey data from 2009 to 2017, we systematically analyzed the temporal and spatial distribution characteristics of beach litter on seven typical beaches of Shandong province in the past 9 years.Then the source analysis of beach litter was conducted.The results showed that the main components of beach litter were plastics, wood products, glass and paper in Shandong province, with the largest amount of plastics accounting for 55.86%.The mean quantity and quality density of beach litter were 75958/km² and 1186.47 kg/km², respectively, and they both showed significant regional differences.There were plenty of small and medium-sized light wastes (74.03%) in beach litters in Shandong province, and their inventory had similarly changed with other monitoring areas of China.For many years, the main sources of beach litter were human coastal activities (54.88%), other refuse (24.59%) and shipping/fishing wastes (10.40%) in Shandong province.The regional statistics indicated that different cities varied in litter sources, which might be related to the economic development, coastal utilization as well as the functional zones in monitoring area of different cities.