A review of end-life management options for marine structures: State of the art, industrial voids, research gaps and strategies for sustainability

End-of-life management for marine structures demands exceptionally sustainability practices due to the potential for environmental and health hazards associated. The purpose of this article is to explain how improved recycling, reusing, and disposal techniques contribute to the marine industry's long-term sustainability. The subject is narrated through six major maritime structural material categories: ferrous, non-ferrous, polymer, inorganic materials, composites, and concrete. With the information gathered, some noticeable institutional voids were identified and discussed with the possible actions to counter them. Environmental sustainability, economic concerns, waste management, and a lack of regulatory execution were identified as critical global issues. It is stressed that the design requirements for marine structures should consider (a) the overall benefits and drawbacks of end-of-life options, as well as (b) the marine structure's lifecycle cost. When adopting design for reuse/recycle concepts, the proposed three-phase design hierarchy would be a valuable tool for structural designers. The degree of sustainability of various end-of-life management solutions is graded using a ranking system. With more research, the ranking system can be developed into a standardised rating model. Overall, the study covers state of the art in the end-of-life management industry and outlines significant global concerns and research gaps while offering answers and techniques for dealing with such issues, ensuring the industry's long-term sustainability.