Work

Tracing the sources of floating plastic in Romanian waters under changing regional pressures through backtracking modeling

Year: 2025

Type: article

Abstract: This study presents an integrated assessment of floating marine macro litter (FMML) distribution and transport in the western Black Sea, based on visual observations conducted during a research cruise in July 2024. Eight transects were surveyed along the Romanian coast, revealing a marked contrast between coastal and offshore FMML densities. While nearshore stations showed relatively low concentrations, offshore transects beyond the Northwestern Shelf (NWS) exhibited densities exceeding 9000 items/km 2 , primarily due to the presence of elongated white plastic strips. Lagrangian backtracking simulations using the LOCATE model identified distinct origin pathways: coastal FMML was linked to riverine systems such as the Danube, Dniester, and Dnieper-Bug, whereas offshore litter appeared to originate near the Crimean Peninsula. Persistent mesoscale cyclonic activity, revealed through analysis of the Q parameter, was found to create convergence zones that facilitate debris accumulation, with one particularly stable gyre located near 32°E and 44°N. These findings suggest the influence of both natural circulation and conflict-driven inputs on FMML distribution. The combined use of observational surveys, transport modeling, and circulation patterns offers a replicable framework for marine litter monitoring and supports science-based management strategies under evolving environmental and geopolitical conditions. • Offshore hotspots with > 9000 plastics km −2 detected in Romanian waters. • Elongated white plastic strips were the dominant items in offshore surveys. • Backtracking indicates Crimea as a potential source region for plastics. • A mesoscale gyre near 32°E–44°N acted as a retention zone for floating debris. • Field data provide new evidence of rising plastic loads in the Black Sea.

Source: The Science of The Total Environment

DOI: 10.1016/j.scitotenv.2025.181035