This integrated solution redefines fish cold chain logistics, combining sustainable packaging, materials science, paper-based sensors, and real-time monitoring. Its core is a reusable transport box made of isothermal Expanded Polypropylene (EPP), incorporating recycled fishing industry materials. Replacing high-impact single-use boxes, it provides passive cooling without external energy, enables rapid sanitization, and extends product lifecycle within a circular economy model. A key innovation is PetriTag®, a patent-pending paper-based label offering real-time visual detection of bacterial contamination. A biopolymer matrix with chromogenic culture media changes color when target microorganisms are present, dynamically assessing freshness beyond static expiration dates. Its multi-spot configuration detects multiple bacterial strains, adding biological safety. The system also integrates IoT traceability, monitoring temperature, geolocation, and asset status, complemented by PetriTag®`s biological risk detection. With 35% of seafood lost along the supply chain and 59 million tons wasted annually in Europe, this scalable, circular solution transforms sustainable food logistics.