This study is a first investigation using WSNs for Mangroves protection and observation at Taiwan. In this investigation, this paper proposes a Natural Ecology Sensing System (NESS). NESS can improve the drawbacks of traditional long-term observation method by providing a real-time and networked surveillance system. This paper considers the practical issues of deploying ecological environment sensors in the Mangroves protection area. In additions, feasible solutions are proposed to achieve sustainable energy supply and reliable data delivery with high accuracy. We also evaluate system performance in terms of energy consumption and packet loss rate at different duty cycles, and compare lifetime and data accuracy with different energy supply sources. According to implementation results, the proposed system is efficient and feasible for Mangroves observation, protection, and surveillance. The main contributions of this study are as follows.