Baited Remote Underwater Video (BRUV) has become a popular technique to survey fish assemblages for a wide range of purposes from ecological monitoring to testing specific ecological hypotheses. BRUV methodology can, however, vary greatly due to logistical reasons to do with the habitats being sampled, the questions being addressed, the equipment being used, and due to historical reasons. In this study, we test whether there are significant differences between estimates of rocky reef fish assemblages, species diversity and relative abundance between different BRUV set times. We sampled fish assemblages on six rocky reefs (20 – 35 m) across two marine parks (Solitary Islands Marine Park: SIMP; Port Stephens Great Lakes Marine Park: PSGLMP; New South Wales). Three locations were surveyed, one in SIMP and two in PSGLMP. At each location replicate BRUVs were deployed for 30 and 60 mins in a ‘no take’ area and a fished area.

Multivariate analyses showed there were no differences in fish assemblages or species richness between 30 and 60 min set times. Snapper Pagrus auratus, showed a significant increase in relative abundance (Max N) between 30 and 60 mins. Piecewise regression analysis of breakpoint times for species accumulation found that there were no significant difference between locations or fished and unfished areas and that mean breakpoint, the time when species accumulation changes, occurred at 12 mins ± 1.04 S.E for all sites combined. This study quantifies either 30 or 60 minutes provides a reasonable estimate of rocky reef fish diversity and relative abundance.