Worldwide, urchins are thought to be regulated by predators, but mechanisms governing Centrostephanus rodgersii (long-spined urchin) across their natural New South Wales (NSW) range are unclear. Generally, it is thought that barrens attributed to C. rodgersii persist because overfishing removes predators that can eat large urchins >100mm Test Diameter (TD) and that barrens are impoverished places where urchins suffer due to having little food. To investigate, we undertook gut content analysis of urchin predators including 250 Sagmariasus verreauxi (eastern rock lobster), 39 Achoerodus viridis (eastern blue groper), and 111 Chrysophyrus auratus (pink snapper), ran feeding trials in mesocosms and tethered 196 urchins in the wild. We also dissected 150 C. rodgersii for gut contents, roe and stable isotope analysis. Our results showed multiple predators capable of handling both large and small C. rodgersii, challenging the predator overfishing model. The impact of lobsters on C. rodgersii appeared low. Additionally, analysis of urchin prey using gut contents and Bayesian stable isotope niche modelling demonstrated an omnivorous diet for C. rodgersii with >85% overlap between barrens and macroalgae habitats. These findings underscore the complexity of predator-prey dynamics within NSW, raising questions about the traditional predator overfishing model and the nature of urchin barrens.