Marine Sanctuaries are one of the key conservation mechanisms established under the Marine Conservation Act. According to Article 8 of the Act, the central competent authority may designate ecologically important marine areas that require special protection and have not already been designated as marine protected areas under other laws as Marine Sanctuaries.

Marine Sanctuaries are intended to strengthen protection for areas containing unique or rare natural resources, habitats of threatened or endangered species, areas with high biodiversity or biological productivity, ecologically fragile environments, relatively undisturbed ecosystems, or significant blue carbon functions. Their designation is therefore based primarily on ecological importance and conservation necessity.

The management system adopts a zoning approach consisting of core zones, buffer zones, and sustainable-use zones. Core zones are subject to the strictest protections and generally prohibit entry by people or vehicles. Buffer zones allow limited activities upon approval, while sustainable-use zones seek to balance marine conservation with compatible and sustainable resource use.

The designation process emphasizes scientific assessment, transparency, and stakeholder participation. Proposed sanctuary plans must undergo inter-agency consultation, public exhibition, public hearings, and review by the Marine Conservation Review Committee. Indigenous peoples, local communities, fishers, and other stakeholders are also consulted throughout the process to enhance policy legitimacy and social consensus.