Mussel farms in the Firth of Thames region of New Zealand have emerged as important habitats for various coastal fish species. The addition of aquaculture structures and cultured bivalves provide both shelter and feeding opportunities. However, increased fish abundance in mussel farms results in increased predation of farmed mussels, with crop losses of up to 100% reported in New Zealand’s mussel aquaculture industry. In this study, remote underwater video (RUV) was used for 6 months to observe fish activity at four different stages of production in mussel farms in the Firth of Thames, New Zealand. The RUV enabled the identification of the fish species inhabiting mussel farms, including the two most commonly observed species that were also responsible for consuming cultured mussels, confirming the effectiveness of RUV methods for this research application.