Marine Debris Project Final Report 2014

Marine litter also appears to have major impacts on biodiversity. Entanglement in fishing gear has beenimplicated as a major threat to a number of marine vertebrates. For instance, it is estimated that between5,000 and 15,000 turtles are entangled each year by derelict fishing gear washing ashore in northernAustralia alone (Wilcox et al. 2014). Ingestion of plastics is also an issue, with over 600 species having beenreported as ingesting plastic (Thompson et al. 2011). Ingestion appears to be having impacts, both directlythrough physical effects on animals and indirectly via concentration and transport of toxins into thedigestive tract of marine species (Day et al. 1985, Tanaka et al. 2013, Rochman et al. 2013, Talsness et al2009, Teuten et al. 2009).While it is clear that plastic debris is an important and growing source of pollution, with a myriad ofimpacts, understanding its sources and trends remains difficult. Collection of data from surface sampling atsea remains limited, largely due to cost. Recent published work which estimated floating plastic debris atthe global scale was based on plastics concentrations data from only 442 sites (Cozar et al. 2014): most seasurface data are sparse or geographically limited. In contrast, there are extensive coastal debris samples,largely from volunteer cleanup programs such as those run by Ocean Conservancy, project AWARE, or theMarine Conservation Society. While these projects sometimes have significant spatial and temporalcoverage, they are typically focused on removal of debris and thus do not follow sampling designs that lendthemselves to analysis. There have been some efforts to develop standardized coastal surveys, linked toenvironmental policy such as the beach litter surveys conducted for the Convention for the Protection ofthe Marine Environment North-East Atlantic (OSPAR 2010, Galgani et al. 2013). However, statisticalanalyses have been designed post hoc to evaluate trends and sources, which has been a major shortcomingin some programs (e.g. Schultz et al. 2013, Sheavly 2010). As governments make policies to address plasticpollution, such as the European Union Marine Strategy Framework Directive, large scale monitoringprograms are emerging in Europe, Australia, the United States and elsewhere (Galgani et al. 2013,Department of Environment, Water, Heritage and the Arts 2009, Sheavly 2007). However, there issignificant discussion over the design, cost, and utility of these monitoring programs (Galgani et al. 2013,Sheavly 2010).Australia has developed a national policy to address marine debris, and in particular its impact on marinewildlife. While there were sporadic data on the distribution, abundance, and type of debris along thecoastline, and to a lesser extent offshore, there was no large scale systematic dataset. In response to thisneed, we developed a large-scale statistically robust coastal survey of debris. Using this dataset we controlfor sampling bias to estimate the distribution of debris along the entire coastline of the Australiancontinent. Using this standardized dataset we investigate the factors influencing the contribution ofHardesty et al. (2014) | 23