Inter-annual variation in the density of anthropogenic debris in the Tasman Sea

An increasing number of studies highlight the risk of plastic pollution in the marine environment. However, systematic longitudinal data on the distribution and abundance of plastic debris remain sparse. Here we present the results of a two-year study of plastic pollution within the Tasman Sea, contrasted with a further year of data from the same region, in order to document how the density of debris varies across years in this area. Surface net tows were collected between Hobart, Tasmania and Sydney, Australia during the spring of 2013 and 2014 and compared with a subset of data from autumn 2012 from the same region. Substantial inter-annual variation in mean plastic abundance was observed over the three year period, ranging from to 248.04-3711.64 pieces km^-2, confirming the need for multiple years of sampling to fully estimate the extent of, and trends in, plastic pollution.