Editorial: Marine Litter Windrows

Our civilization produced about 8,300 Mt of synthetic polymers to date (Geyer et al., 2017), and the seas and oceans are pooling much of them (González-Fernández et al., 2021). Figuring out how all this marine litter moves and where it accumulates is a challenging task (Van Sebille et al., 2020). In some cases, we have been able to describe the distribution of plastics at a large-scale and associated to steady circulation patterns (e.g., Cózar et al., 2014), but understanding plastic distribution at small scale is more complex, due to the also complex ocean dynamics at such scales, and the much shorter-lived structures resulting from it. Actually, if we look at the ocean surface, it is common to see floating natural and man-made materials aggregated in small dense patches, often arranged in parallel lines sometime more than one kilometer long. They are traditionally called windrows in the scientific literature (Faller and Woodcock, 1964; Owen, 1965; Craik, 1970; Leibovich, 1983); foam lines, slicks, drift lines, rip lines, filaments, or streaks are synonyms. There is no definitive classification, but a listing of them would include windrows generated by tidal fronts, shelf-break fronts, upwelling fronts, river plumes, estuarine fronts, fronts associated with the convergence or divergence of water masses in the open ocean, frontal eddies, caused by internal waves, and fronts associated with geomorphologic features such as headlands, islands, and canyons (Mann and Lazier, 2006). All these processes are capable to create the surface evidence that we call windrows. In this volume, some aspects of ocean windrows are presented, focusing on the interaction of windrows with marine debris and related problems and opportunities. [...]