Development of an individual-based tag recapture model to benchmark biomass and harvest rates in an iconic lobster fishery

The West Coast Rock Lobster Managed Fishery (WCRLMF) moved from input to output controls in 2010. This change affected the relativity of fishery-based data sources (e.g., catch rates and landed size composition), making assessment fishery problematic. A novel examination stock dynamics was required ensure robustness associated management arrangements. study derived estimates current biomass levels harvest release over 60,000 tagged western rock lobsters ( Panulirus cygnus ). “Brownie” tag-recapture (BTR) model initially implemented provide an on a fishery-wide basis. Estimates this were compared those purpose-built individual-based (IBM) that accounted for sex, size, month, location-specific changes catchability. two models produced similar scale—harvest rate (HR 0.26 vs 0.30, respectively) legal-sized (about 24,500 20,735 t, respectively)—while IBM also provided far finer spatial temporal scale. Both indicate WCRLMF is currently very sustainable condition being fished at below maximum economic yield mey about 0.39). These findings concert with based separate catch-rate population models, integrated biomass-dynamics model. Such strong agreement among all provides great certainty important marine resource.