Mangroves are a significant kind of coastal vegetation that develops along tropical and subtropical coastlines and serves an essential role in coastal ecosystems. The rapid development of coastal cities, growing urbanization, unexpected recreational activities, and the rise of aquaculture in mangrove forests across the globe have all proven a threat to these critical ecosystems. However, mangrove algae help to reduce pollution. Furthermore, mangrove-associated algae remove a variety of toxic contaminants from the mangrove environment. This chapter focused on the use of algae in bioremediation, which has been demonstrated to increase as a result of environmental issues and the flexibility of microalgae. Biodegradation and bioremediation, which employs algae to remove a variety of organic pollutants, are feasible and show great potential. Algal biodegradation of organic waste is an ecological process with less environmental consequences than mechanical, physical, and chemical methods of removing organic pollutants. The benefits of algae-based biological remediation include higher yields of biomass and its ability to accumulate, degrade xenobiotics, detoxify, and remove harmful substances.