Rapid mangrove dieback in the northern Persian Gulf driven by anthropogenic activities and environmental stressors

The mangrove ecosystems in the northern Persian Gulf are unique, yet highly vulnerable habitats that face a range of environmental and anthropogenic pressures. This study assesses the ecological dynamics of the Mangroves of Dayyer City (MDC) in the northern Persian Gulf using a multidimensional approach involving satellite-derived, drone-based, and field-measured data. Satellite imagery from Google Earth (2011–2022) reveals fluctuations in the MDC area, with notable afforestation efforts until 2018 followed by rapid degradation. The mangrove forest, initially covering ~ 2.2 ha in 2011, expanded to ~ 3.2 ha by 2015 due to afforestation efforts but declined to ~ 1.7 ha by June 2022. The construction of a nonstandard road and a bridge in 2018 obstructed freshwater flow from upper areas, emerging as a major factor in this degradation. Drone-based observations in March 2023 provided a detailed map, revealing that ~ 44% of healthy mangroves had been damaged. Field measurements conducted in November 2023 showed higher salinity levels at MDC compared to other adjacent mangrove areas (Nayband and Melgonzeh). Principal component analysis (PCA) showed that the first two components explained 99.7% of the variability in the environmental data, with water temperature and salinity/dissolved oxygen being the key factors. This study emphasizes the role of human impact, particularly the obstruction of freshwater flow, in degrading mangrove ecosystems, thereby enhancing our understanding of the complex interactions affecting these valuable coastal habitats.