Seite - 241 - in Freshwater Microplastics - Emerging Environmental Contaminants?

While regulatorymeasures canbeclearly addressed toone stakeholder at a certain stageofproduct life (e.g., producer,manufacturer, consumer,wastemanager), it is more difficult to identify the correct addressee for plastics already released to the environment. So far, due to the complexity of this issue, it is not clear which (policy) areas have to act first, which concepts would be necessary, and what requirements are needed to promote actions beyond those already initiated. With regard to aquatic environments, (micro)plastics aremainly considered by marinescienceandpolicyand, for instance, implementedinto theEuropeanMarine StrategyFrameworkDirective (MSFD, [4], descriptor 10 “marine litter”).A com- prehensive overview on regulation and management of marine (plastic) litter is provided byChen [5]. However, it is assumed that approximately 80%ofmarine debris is land based [6], even though there is a lack of available quantitative evidence supporting this statement. Rivers are one of the entry pathways for (micro)plastics intomarineecosystems.However, theplastic issue isnot explicitly addressed inanyregulationregardingfreshwaterenvironmentssofar. Incontrast to theMSFD, the 8 years older EuropeanWater Framework Directive (WFD, [7]) does not include the issueof plastic pollution. The management of MPs in aquatic systems is even more complex than the regulationofmacroplastic litter.Manyquestionsneed tobeanswered, startingwith a commonly accepteddefinitionofMPs.Knowledgegaps about sources, transport pathways, andvolumesand theenvironmental fateof the small particleswith their heterogeneous characteristics have to be filled, not at least to define adequate methods for a standardized freshwatermonitoring ofMPs. The adaption of expo- sure and hazard assessment to evaluate the risk of freshwaterMPs as particulate stressors is oneof themajor challenges for regulationandmanagement.Currently, essential yet unanswered questions refer to the ecological impacts of plastics on today’s environment, let alone their long-termconsequences. Notwithstanding, the issue of (micro)plastic pollution in freshwater environ- ments isoneof themajorbut least studiedhumanpressuresonaquaticecosystems, and further research is requiredon this issue.Nevertheless, there aremany indica- tions for adverse environmental impacts that should lead to preventivemeasures. As stated inArticle 191of theLisbonTreaty [8], theEuropeanCommunitypolicy ontheenvironment“[. . .] shallaimatahigh levelofprotection taking intoaccount the diversity of situations in the various regions of theUnion. It shall be based on theprecautionaryprincipleandon theprinciples thatpreventiveactionshouldbe taken, thatenvironmentaldamageshouldasapriorityberectifiedatsourceandthat the polluter should pay.”Therefore, regulation andmanagement should dealwith the issue of freshwater (micro)plastics. This chapter provides a rough overview of the existing regulatory instruments developed at international and national levels which address or at least touch the topic of freshwater (micro)plastics. It does not intend to develop new regulatory approaches dealing with the issue but highlights challenges for regulation and management.Despite the regulation of (micro)plastics being already addressed in afewinitiatives, it isstill far fromacomprehensivemanagement.Reasonsmightbe various as (micro)plastics pose new challenges for freshwater monitoring and regulation.Thiswillbediscussed in the thirdsectionof thischapter.Acompilation FreshwaterMicroplastics:Challenges forRegulation andManagement 241