Marine organic waste valorization on seafood-based industry development: A review on circular bioeconomy and Technology Readiness Level (TRL) perspectives

Marine organic waste, including fish processing byproducts, shellfish residues, aquaculture waste, aquatic plant biomass, and coastal beach wrack, represents an abundant yet underutilized biomass resource with significant potential for supporting a circular bioeconomy. This review comprehensively evaluates recent advances in the valorization of these marine waste streams through sustainable biotechnological and thermochemical approaches. The review identifies fish waste, shellfish waste, macroalgae, microalgae, aquaculture residues, and coastal biomass as major feedstocks for producing high-value bioproducts, including collagen, gelatin, chitin, chitosan, bioactive peptides, omega-3 fatty acids, enzymes, biofertilizers, bioplastics, biochar, and biofuels. Emerging extraction technologies, including enzymatic hydrolysis, ultrasound-assisted extraction, microwave-assisted processing, supercritical fluid extraction, and microbial fermentation, are highlighted for their potential to improve product recovery while reducing environmental impacts. Furthermore, this review summarizes the current commercialization status of marine waste-derived products in India by integrating economic assessments, industrial applications, and Technology Readiness Level (TRL) analysis, demonstrating that conventional products such as fish meal, fish oil, chitin, chitosan, agar, and carrageenan have reached commercial maturity (TRL 8–9), whereas advanced biomaterials, bioactive compounds, and bioenergy technologies remain at intermediate developmental stages (TRL 3–7). The review also proposes a circular bioeconomy framework that links waste generation, valorization technologies, product development, commercialization, and resource recirculation to enhance sustainability. Despite considerable progress, challenges related to feedstock variability, processing costs, technology scalability, regulatory support, and industrial integration continue to limit large-scale implementation. Overall, this review identifies critical research priorities and policy directions required to accelerate the transition from waste disposal to high-value resource recovery, thereby supporting sustainable blue economy development and achieving the United Nations Sustainable Development Goals.