Mangroves are of great ecological significance and are the dynamic hub of the oceanic ecosystem. They provide ecosystem services and play an important role in climate change, nutrient fluidities, yield, and biodiversity of organisms. A total of 1533 species are associated with mangroves, and 15 per cent of species are threatened with the verge of extinction. The main causes of mangrove loss and degradation are deforestation, tourism, and global warming. The global average of carbon stocks of mangroves is around 1,000 tons of carbon per hectare, including soil carbon. Although mangroves make up only 0.5% of global coastal area, they store 10–15% of coastal sediment carbon storage and export 10–11% of the particulate terrestrial carbon to the ocean. The annual carbon sequestration rate is ten times more than mature tropical forests. Mangrove forests and coastal marshes are typically considered nitrogen-limited ecosystem because of their high primary productivity. The mangrove plants are highly efficient at utilizing soil nitrogen, making them an important sink for excess nitrogen upstream. Mangrove forests are at risk due to human activities and climatic conditions. The mangrove ecosystem is affected due to changes in temperature, sea level, atmospheric carbon dioxide, intensity and frequency of storms, and changes in precipitation pattern. Management of mangrove refers to the systematic approach of conservation and restoration of wetlands, sustainable use, monitoring and research, international and national treaty, and policies. This involves implementing strategies to maintain ecological functions and protection of mangrove biodiversity. Mangrove areas can be managed properly, and sustainable use of mangroves can increase the demand of water supply and food, reduce shoreline erosion, increase carbon sequestration, etc. This chapter focuses on the mangrove ecosystem and its role in nutrient cycling, carbon fixation, and climate change management.