Unprocessed seafood products like smoked salmon, gravlax, cooked shrimp, and vacuum-packed fish fillets are at risk of contamination by harmful microorganisms. Despite strict hygiene measures, problems in maintaining the cold chain—such as temperature fluctuations—can allow dangerous bacteria like Listeria monocytogenes, Vibrio, or Salmonella to grow. These bacteria can cause illness, especially in vulnerable groups like pregnant women, the elderly, and those with weakened immune systems. Additionally, spoilage bacteria can degrade the taste, smell, and texture of seafood, leading to waste. It is estimated that about 30% of the total fish caught is lost due to microbial spoilage, adding to the economic and health challenges in the seafood industry. To address these issues, the food industry is exploring new preservation methods. Traditional approaches such as salt and smoking are being reduced for health and taste reasons, and consumers are increasingly wary of chemical preservatives. This has led to growing interest in biopreservation—a natural method that uses beneficial bacteria to prevent harmful ones. The concept may sound counterintuitive, but in nature, certain bacteria compete with others by producing antimicrobial substances or using up nutrients. Scientists are harnessing this natural process to enhance food safety and quality without altering taste or texture. Lactic acid bacteria (LAB) are among the most promising candidates for biopreservation. These bacteria are generally considered safe and are familiar to many through products like yogurt. Some LAB are naturally found in seafood, such as in smoked salmon, which makes them ideal for use in preserving these products. Over the past 30 years, researchers at Ifremer, in collaboration with ONIRIS VetAgroBio Nantes, have collected and tested thousands of bacterial strains. These strains are adapted to the specific conditions of seafood—such as low temperatures and low sugar content—and are tested for their ability to inhibit harmful bacteria without affecting the food’s sensory qualities. Through rigorous testing, scientists have identified several effective strains, including Carnobacterium maltaromaticum, Carnobacterium divergens, and Lactococcus piscium, which help limit the growth of Listeria monocytogenes in products like smoked salmon and cooked shrimp. These bacteria also slow down spoilage, offering a dual benefit. Another strain, Latilactobacillus sakei, has been patented for its ability to prevent the formation of histamine in tuna, a harmful compound that can cause food poisoning. These advancements are now being applied in the food industry, with commercial licenses issued to producers. Future research aims to expand biopreservation into other food products, such as meat and dairy, and to improve its use in less processed and more durable packaging. With continued development, biopreservation could become a key tool in the global effort to preserve food sustainably and safely.