Hybrid Monitoring of Mangroves in the Kamiali Wildlife Management Area, Papua New Guinea

Abstract

The Mangrove forests underpin coastal resilience, biodiversity, and livelihoods across Papua New Guinea, yet conventional monitoring in the Kamiali Wildlife Management Area (KWMA) remains sporadic and invasive. This study synthesizes evidence from a PRISMA-guided systematic literature review and evaluates a suite of complementary technologies—UAV-based multispectral/hyperspectral and LiDAR sensing, SAR and optical satellites, environmental DNA (eDNA) metabarcoding, passive acoustic monitoring (PAM), UAV thermal imaging, and uncrewed surface vessels (USVs)—to propose a hybrid monitoring framework tailored to the biophysical and social conditions of the KWMA. Across recent sources, we assess detection capacities, spatiotemporal coverage, cost efficiency, and operational feasibility under crocodile-inhabited tidal channels, dense canopies, and limited access, and we integrate outputs with global mangrove watch classifications and community priorities to inform conservation decisions and climate adaptation. The findings indicate that UAV LiDAR and hyperspectral imaging resolve canopy structure, height, and dieback at plot scales; SAR plus optical imagery enables wall-to-wall change detection across tidal regimes; eDNA reveals cryptic and rare taxa while reducing field disturbance; PAM and thermal imaging track the seasonal activity of birds, bats, and other fauna; and USVs extend water quality and geomorphological observations along hazardous channels. A cost comparison revealed that mixed sensor stacks outperform single-method approaches in terms of accuracy, repeatability, and safety when paired with streamlined field protocols. To ensure equitable practice, the framework embeds free, prior, and informed consent; data sovereignty; and coproduction with local stewards, coupled with training pathways via UN volunteers. We outline stepwise protocols for sensor selection, sampling design, QA/QC, and data fusion, culminating in decision-ready indicators aligned with reporting and sustainable development goals. The resulting roadmap is pilot-ready for KWMA and transferable to similar Pacific contexts, strengthening evidence-based governance while building local capacity. This study demonstrates how combining aerial, satellite, molecular, acoustic, thermal, and surface-vessel observations can deliver rigorous, cost-aware mangrove monitoring that advances biodiversity conservation, climate resilience, and community well-being.