Many shark species undertake large-scale migrations and can impact the ecosystems they frequent, however migration in benthic sharks is largely understudied. In this study, we applied stable isotope analysis to investigate spatial and temporal feeding habits of a migratory benthic shark, Heterodontus portusjacksoni. Port Jackson sharks were used as a model species as they migrate annually in large numbers and their impact on resource availability in coastal ecosystems could be substantial. Samples were collected from wild sharks throughout their four-month breeding season (July-October) and analysed for δ13C and δ15N. Multiple tissue types (whole blood, plasma and fin tissue) were used to gain a snapshot of movement and feeding habits over different time scales. Isotopic ratio δ15N of whole blood indicated that three NSW shark populations utilised similar food sources (Jervis Bay 12.89‰, Sydney 13.38‰ and Port Stephens 13.08‰), whilst the Melbourne population appeared to feed at a higher trophic level (δ15N=14.96‰). There was also evidence of a potential diet shift during migration as both δ13C and δ15N of Jervis Bay sharks increased over the breeding season when sharks were resident. These data indicate that benthic sharks may feed opportunistically to take advantage of locally abundant prey items.