Multi Year Observations Reveal Variability in Residence of a Tropical Demersal Fish, Lethrinus nebulosus: Implications for Spatial Management

More than half of the spangled emperor (Lethrinus nebulosus) population moves beyond the average sanctuary zone size within the Ningaloo Reef Marine Park, despite exhibiting stable and small home ranges over one to two years. This finding challenges the assumption that current no-take zones adequately protect this species. Researchers tagged 84 fish with internal acoustic tags across lagoon and reef slope habitats, both inside and adjacent to the Mangrove Bay Sanctuary zone, tracking their movements for over a year. Kernel Utilization Distribution (KUD) analysis revealed that while resident fish had an average home range of 8.5±0.5 km²—smaller than the sanctuary zones—they often moved outside these protected areas over time. Long-term monitoring also identified spawning-related movements, highlighting the need for larger or more strategically placed sanctuaries to effectively conserve this species.

Pillans, R. D., Bearham, D., Boomer, A., Downie, R., Patterson, T. A., Thomson, D. P., & Babcock, R. C. (2014). Multi Year Observations Reveal Variability in Residence of a Tropical Demersal Fish, Lethrinus nebulosus: Implications for Spatial Management. PLoS ONE, 9(9), e105507. https://doi.org/10.1371/journal.pone.0105507