Navigation-Induced Ecological Risks in Mangrove-Fringed Canals: A Review of Monitoring, Risk Assessment and Adaptive Scheduling

Navigation management in ecologically sensitive canals requires integrated decisions about what to monitor, how ecological risk should be assessed, and how risk information should influence operations. This structured narrative review synthesizes evidence along a navigation pressure–environmental pathway–mangrove receptor–ecological risk–management response chain using an explicit search and synthesis protocol. Unlike existing environmental risk assessment and ecosystem-based management frameworks, it treats navigation as a controllable operational pressure and links monitoring indicators directly to scheduling constraints. We examine vessel wakes, propeller jets, and lock operations; hydrodynamic, water-quality, and sediment responses; and mangrove sensitivity to hydroperiod, salinity, turbidity, suspended sediment, and depositional change. A six-layer indicator system covers navigation pressure, hydrodynamic processes, water and sediment conditions, ecological receptors, natural background, and management performance. Risk is structured around hazard, exposure, vulnerability, and recovery capacity. We compare four complementary interfaces for translating risk into operational decisions: fixed limits, suitability ranges, cumulative risk budgets or dose–response constraints, and probabilistic safety constraints. Evidence remains strongest within individual disciplines, whereas synchronized event-based monitoring, background correction, locally validated risk functions, and closed-loop monitoring–assessment–scheduling remain limited. Future research should prioritize causal attribution, multi-stressor cumulative exposure, dynamic risk boundaries, uncertainty propagation, and adaptive decision support for environmentally sensitive canal management.