Same but Different: A Framework to Design and Compare Riverbank Plastic Monitoring Strategies

Abstract

Plastic pollution in rivers negatively impacts human livelihood and aquatic ecosystems. Monitoring data are crucial for a better understanding of sources, sinks and transport mechanisms of riverine macroplastics. In turn, such understanding is key to develop effective plastic pollution prevention, mitigation, and removal strategies. Riverine plastic is mostly studied through the monitoring of floating plastic and through the quantification of plastic deposited on riverbanks. Existing riverbank plastic measurement methods vary greatly, which complicates direct comparison of data collected with different monitoring strategies. We present a framework to better compare and to aid the design of riverbank plastic monitoring methods, which is based on four common elements distilled from riverbank (plastic) litter monitoring methods currently in use. This framework can be used by scientists and practitioners to find the right trade-offs between the data required to answer specific research questions, and the available resources. Subsequently, we use the framework to suggest effective monitoring strategies for four frequently asked research questions. With this paper, we aim to provide a first step toward harmonization of riverbank plastic litter monitoring efforts.

Plastic Pollution Research in Indonesia: State of Science and Future Research Directions to Reduce Impacts

“…Reliable and frequent data on plastic pollution and its effects on fauna and ecosystems are required for the development and assessment of policy measures aimed to reduce plastic emissions to the oceans (Conchubhair et al, 2019;Owens and Kamil, 2020;Vriend et al, 2020). Moreover, data on exposure and toxicity are needed to assess microplastics' human health risks from exposure to, for example, contaminated seafood (Hantoro et al, 2019).…”

Plastic Hotspot Mapping in Urban Water Systems

“…Due to its simple nature, data collection may also be done through citizen science efforts. Litter on Dutch and German riverbanks is already being monitored by trained citizens (e.g., Kiessling et al [18], Vriend et al [19]). New mobile applications, such as CrowdWater [20,26], have been developed to facilitate citizen science plastic data collection in urban and natural water systems.…”

“…Note that the actual categorization protocol can be changed according to the research question or goal of the plastic hotspot mapping. Examples of other categorization protocols can be found in Vriend et al (2020).…”

“…In this study, we expressed plastic density in items/m and items/km canal length, as this is a common unit to express riverbank plastic data (Vriend et al, 2020). Future studies may consider also normalizing over the canal or river width, allowing the expression of plastic density in items per surface area of the water system.…”

“…The latter includes identifying the most effective cleanup routes for mobile cleanup initiatives (e.g., Plastic Spotter Canoe Fleet; Citizen Science Lab, [15]) or permanent waste collection devices (e.g., Seabin Project [16]) or The Great Bubble Barrier [17]). As no additional equipment is required, the method can also be used for data collection through citizen science, such as done previously for German and Dutch riverbanks [18,19]. Data collection can be done using the mobile citizen science app CrowdWater, which includes a module for measuring plastics in urban and natural water systems [20].…”