The Surfing for Science citizen science project: 5 years monitoring floating microplastics in the nearshore

Since 2020, the Surfing for Science project has provided data on the abundance and origin of floating microplastics in the nearshore of N and NE Iberian Peninsula and the Balearic Islands. Over the past five years, we have actively involved citizens and several social, environmental and sports associations to collect scientific samples during 1 year by towing a newly designed manta trawl from paddle surf boards, kayaks, etc. The tracks are being recorded using a smart-phone built-in GPS and uploaded. Samples are sent to the laboratory at the University of Barcelona, where microplastic extraction, quantification (number of microplastics m-2 and weight of plastic m-2), and characterization (size, shape, colour, polymer) is being performed. Microplastics are scanned and the image processed and uploaded to the Instagram social network account accompanied by the code of the sample, the map of the transect performed, and the association involved. To date, we have collected more than 400 samples in nearly 30 locations, including a 5 years' time series in one of the most visited and well-known beach in the city of Barcelona, totaling ¿100,000 plastics. During the last years we have overcome several challenges such as the high amounts of items in the samples or how to share results with citizens. We have developed new protocols for semi-automatic counting and particle categorization, automatic file management, data processing, color determination and microplastic category classification. We utilize Instagram as a channel to share scientific data and we produced t-shirts featuring results, turning individuals that wear these t-shirts into "walking disseminators" and involving citizens scientists in sharing results, and we have developed educational resources. We continue to strive for the best communication and feedback to all citizens to maximize the dissemination of the results and to serve as a resource for the administration, consumers, producers and policymakers. Also see: https://micro2024.sciencesconf.org/559616/document