Simulated mark-recovery for spatial assessment of a spiny lobster (Panulirus argus) fishery

- We simulate scenarios representing spiny lobster distribution at Glover's Reef Marine Reserve, Belize.
- We examine how no-take reserves bias stock assessments that rely solely on fishery-dependent data.
- We evaluate whether a mark-recovery design can be robust to uncertainty about transfer rates between fished and non-fished areas.
- Fishing mortality can usually be accurately estimated by mark-recovery without prior knowledge of fish transfer rates.

Marine reserves are becoming widely implemented along with conventional fisheries controls as integrated approaches to fisheries management. The restricted spatial distribution of fishing effort, relative to the spatial distribution of fish stocks that may be partially protected by marine reserves, often necessitates spatial considerations in the design of monitoring and stock assessment. Simulation modeling was used to evaluate whether a mark-recovery design could be used to accurately estimate fishing mortality rates without information about movement rates being available to the assessment procedure. A spatially-explicit individual-based simulation was developed with environmental characteristics of Glover's Reef Marine Reserve, Belize and with biological characteristics of a fished population of Caribbean spiny lobster (Panulirus argus). Accuracy of fishing mortality estimates depended on whether these estimates were calculated for the fished area only or for the entire stock. Stock-wide fishing mortality estimates could usually be obtained that were robust to uncertainty about dispersive movement. We discuss results in the context of managing fisheries based on the status of fished areas alone or on the entire stock and discuss the necessity for information about fish movement for accurate assessment of stocks managed using marine reserves.