The probiotic playbook: approaches for pathogen control in aquaculture

Farmed salmon and oysters face constant disease pressure, and antibiotics alone cannot solve it. This PhD research looks for answers in the sea itself, using bacteria that naturally live alongside the animals they are meant to protect. Testing these probiotics under real disease challenges led to a promising candidate strain, and revealed that its origin and the timing of its use were decisive for how well it worked. Bacteria drawn from the host's own environment, delivered at the right stage of development, protected animals more reliably than strains borrowed from elsewhere, even without permanently colonising the host. These findings offer a practical, more sustainable strategy for preventing disease in fish and shellfish farming.