Emerging mycobacterial threats in Mediterranean aquaculture: implications for marine biodiversity, public health, and industry sustainability.

Access to clean water is a fundamental Sustainable Development Goal that is increasingly undermined by emerging microbial contaminants linked to urbanization, pollution, overfishing, and climate change. This paper investigates the rising incidence of mycobacterial infections in aquatic environments, from potable and surface waters to marine and aquaculture systems, with a particular focus on the Mediterranean Sea. The region, a biodiversity hotspot, exemplifies how climate-induced thermal shifts, combined with anthropogenic pressures, enhance pathogen survival and disease transmission in fish, especially in species with limited thermoregulation. The study synthesizes evidence on the global distribution of various Mycobacterium species, their modes of transmission, and their clinical impacts on a wide range of aquatic organisms. It further explores the challenges posed by ineffective water disinfection, biofilm-associated persistence, and regulatory gaps that complicate disease management. The findings underline the critical need for integrated public health strategies and sustainable aquaculture practices to mitigate the dual threats to marine biodiversity and human health posed by these emerging infections.