Evaluating the impact of northwest African upwelling-derived marine litter on animal entanglement in the Canary Islands

Abstract

Marine debris, particularly that derived from fisheries, poses a serious threat to marine ecosystems in the Canary Islands. This study integrates a Lagrangian modeling approach with observational data to investigate the transport routes, origins, and ecological impacts of floating litter, particularly on sea turtles and cetaceans, in three Special Areas of Conservation (SACs): Tenerife, Gran Canaria, and Fuerteventura. Results indicate that the Canary Current, coastal upwelling, and mesoscale eddies play a central role in the advection and seasonal accumulation of marine debris in these regions. Entanglement was found to be the most significant threat to sea turtles (45%), while cetaceans were more affected by bycatch and vessel strikes. Most debris analyzed was plastic, with fishing gear, raffia sacks, and packaging materials being the most frequent. Backward trajectory simulations suggest that a significant portion of this debris originates from northwest African ports. These findings underscore the urgent need to improve marine waste management, implement effective monitoring, and foster international cooperation for mitigating cross-border marine pollution.