Mangrove fungi play a crucial role in the ecosystem, supporting both biotic and abiotic components. Fungi support the eco-friendly process of composting and maintaining healthy habitats. Mangrove fungi form symbiotic relationships with rainforest trees. Fungi are an essential part in biodegradation and bioremediation, breaking down organic matter and utilising the recycled products. These processes are necessary for conserving fertile and productive soil throughout the entire ecosystem. Various fungal strains are used in bioremediation to clean pollutants such as oil spills, plastics, hydrocarbons, phenols, heavy metals, and contaminants from soil and water. Biodegradation by fungi involves enzymes, primarily lignin and cellulose, that convert complex organic molecules into simpler compounds, contributing to the recycling process. This chapter specifies that fungi play a crucial role in degradation and contribute to maintaining ecosystem stability.