Unmanned Vehicle and Hyperspectral Imager for a More Rapid Microplastics Sampling and Analysis

In this paper, we present a proof-of-concept study aiming to improve the sampling and analysis of microplastics (MPs) by implementing a novel methodology combining an autonomous surface vehicle and a near-infrared hyperspectral imager (HSI). The field study was conducted from the 2nd to the 5th of August 2022 at Runde – a well-known bird preservation island on the Western coast of Norway. Over 35 samples from two different locations (Exposed (A) and Sheltered (B)), MPs concentration was at its highest (0.511 MPs/m3) in location A. During the four days of sampling, at least 25 % of the data did not detect any MPs (0 MPs/m3). Thus, we showcase an easy repeatable method towards the assessment of high variable MPs concentration using a Portable Catamaran Drones (PCD) and a near-infrared hyperspectral imager (HSI). The results from HSI were compared against Attenuated Total Reflection Fourier-Transform infrared (ATR-FTIR). No significant difference ($\mathrm{P} > 0.05$) found at location A indicated that both instruments can provide accurate MPs concentration. A potential future correlation between MPs concentration and Key Environmental Variables (KEVs) could help to contribute to the modeling and policymaking world.