Background
Recreational fishing is a popular activity worldwide with significant socio-economic contributions to society, but also presents environmental management challenges that are now increasingly being addressed through no-take temporal closures (NTTCs). Spatial no-take zones (NTZs) are also progressively being established for conservation purposes with debate remaining about their effectiveness for achieving fisheries management goals.
Methods
We developed a fine spatial and temporal scale simulation model, including both fish and fisher behaviours, to explore population and catch implications of spatial and temporal management options. We applied this model to spangled emperor (Lethrinus nebulosus) in the Ningaloo World Heritage Area (WHA), a popular destination for recreational fishing in Australia. Four management scenarios were compared including the current arrangement of NTZs and three hypothetical scenarios; NTTCs only, combined NTTCs and NTZs, and a scenario with no spatial or temporal management.
Results
Simulation results suggest that despite initial declines in spawning biomass, NTZs increased population biomass over time due to protection of mature fish in closed areas. Likewise, results indicate NTTCs led to biomass increasing over the modelled time period. Predicted population trends for both temporal and spatial management scenarios were strongly influenced by assumptions relating to fishing effort, fish movement rates and home range size.
Conclusions
Overall, the simulated results suggest that combining both NTTCs and NTZs, consistently lead to the best outcomes for fish populations, catch and CPUE near boat ramps. Our fine spatial and temporal scale model, accounting for important aspects of both fish and fisher behaviour, provides a valuable tool for demonstrating how spatial and temporal management options can be integrated to maximise conservation and recreational fisheries benefits.