Ocean plays a significant role in energy production, human health and economy. Seawater, seaweed, microalgae, yeast, bacteria act as feedstock for biofuels and bioproducts. This book focuses on the application of marine biomass for production of energy, fertilizers, nutraceuticals, pharmaceuticals, cosmetics, bioplastics and other value-added products. It presents technological advancements and optimization strategies for enhancing process efficiency, overcoming challenges and maximizing the potential of marine-based biorefinery. It also describes how marine resources can be applied to wastewater treatment, eco-restoration, environment protection and sustainable development.