Filling the Gap: A Comprehensive Freshwater Network to Map Microplastics across Ecological Gradients in Argentina

The first comprehensive freshwater microplastics monitoring initiative is underway in South America, focusing on lakes, shallow lakes, reservoirs, streams, and rivers from Argentina. The project Monitoring and Analysis of Plastic Pollution in Aquatic Environments (MappA) aims to implement a standardized methodology to comprehensively understand microplastics' presence, characteristics, and distribution within these water bodies. Building upon the successes of prior international collaborations (Nava et al. 2023), Dr. Maria B. Alfonso, based at Kyushu University, Japan, is leading the collaborative effort. Engaging 51 experts in aquatic science from 31 renowned institutes and research centers across Argentina, MappA is currently developing an expansive microplastics study. This ambitious project encompasses 117 diverse study sites spanning 21 lakes, 25 shallow lakes, 7 reservoirs, 44 rivers, and 20 streams, covering most of the main watershed areas of the country (Fig. 1). The global concern over environmental issues, particularly the increasing threat of plastic pollution, has compelled a focused investigation of its prevalence in aquatic systems. Initial microplastics research primarily focused on their prevalence in marine systems, dating back to the 1970s; the attention towards microplastics in freshwater habitats is a comparatively recent initiative that emerged in the last two decades. Due to their location in the landscape, freshwater systems can act as either pathways or sinks for microplastics that reach the systems by runoff or atmospheric deposition. Most research studies on freshwater environments have focused on the Global North, so Argentina's vast territory, characterized by varying climate and geography, offers a unique opportunity to analyze the challenges posed by the presence, abundance, and distribution of microplastics. In recent years, microplastic studies in the country have expanded, yet they remain limited and applied diverse sampling methodologies (e.g., Alfonso et al. 2020a, b; Kittner et al. 2022; Buteler et al. 2023; Garello et al. 2023). The study sites included within MappA are located across the latitudinal extension of the country (covering an area of 2.8 million km2 from 24°S to 54°S), encompassing an extensive gradient of human impact (e.g., from urban areas to remote Patagonia), and a wide variety of ecosystems (e.g., from subtropical to subantarctic; and from rainforest to deserts) with diverse freshwater bodies (Fig. 1). Our main goal is to establish a coordinated monitoring program for Argentina's freshwater bodies. By employing a standardized methodology across sites, the study aims to provide a comprehensive understanding of the prevalence and characteristics of microplastics and the effect of climate and anthropogenic variables (detailed further below) on the presence, abundance, and distribution of microplastics. This project seeks to fill a critical knowledge gap, not only for microplastic research in freshwater environments but also for the Global South, offering insights into the scope of microplastic pollution and its potential implications for aquatic ecosystems, and with the possibility to expand to other countries in the near future. A first sampling was ongoing during the Southern Hemisphere summer (December 2023–March 2024) under the same monitoring protocols designed for these diverse aquatic systems and based on international guidelines. Protocols and dataset output of the project will be open to the community following the FAIR Data Principles (Findable, Accessible, Interoperable, and Reusable). The standardized methodology created by the MappA community is available in Spanish and English versions (https://zenodo.org/communities/mappa). The obtained dataset will include information on microplastics (abundance, shape, size, color, polymer types), anthropogenic influence (land use, population, distance from urban centers/roads, etc.), and environmental variables (temperature, precipitation, surface area, water depth, residence time, water flow, etc.) for each study site. The societal relevance of this research lies in creating an interdisciplinary and collaborative network of researchers with the potential to inform policy, drive conservation efforts, and raise public awareness about these emergent pollutants. Understanding the presence and nature of microplastics in Argentina's freshwater systems contributes to global knowledge on plastic pollution and provides local communities, policymakers, and governments with essential information to develop targeted interventions. Furthermore, this initiative brings together aquatic experts from across the country, tightening the research community, and providing future opportunities for networking, a way of doing science that has been proven to be a successful model for solving aquatic ecological issues worldwide. Ultimately, the research promises to foster sustainable practices and safeguard invaluable freshwater resources that support ecological diversity and human well-being. We encourage anyone interested to get involved or learn more about the project by contacting the project leader (Dr. María Belén Alfonso; [email protected]). MBA, Conceptualization; Formal analysis; Investigation; Methodology; Roles/Writing – original draft; Funding acquisition; Project administration, FS, Investigation; Writing – Review & Editing, LBE., Investigation; Writing – Review & Editing, Visualization, AI, Writing – Review & Editing, Funding acquisition, LB, Sample processing; Writing – Review & Editing, MSA, RA, KKA, LA, ASAM, YAR, AHA, EB, GAB, MCMB, LMB, JC, CYDP, BD, YD, SLD, SAE, MEP, MF, MOF, MSF, MF, CF, MSG, AG, MG, MLG, AEG, JAJ, PAM, GAM, CN, PDN, NAO, MLP, RSP, AP, MR, MCR, GNR, JMR, LR, PR, MCMR, LMS, LS, CS, MT, LTH, MV, AMV, NCYV, Investigation; Writing – Review & Editing. This publication was supported by the project “Data Operation and Management of the Marine Plastic Litter Mapping Database and Promotion of International Data Aggregation” funded by the Ministry of the Environment, Government of Japan (MOEJ).