Effects of Assessment Frequency and Data Lag on Mid-Atlantic Harvest Control Rule Performance

Federally managed fisheries have recently been required to establish acceptable biological catch limits.  This requirement has resulted in an increase in the number of assessments that must be conducted, with some stocks being assessed less frequently, but these changes have caused concern about the effect of reduced assessment frequency on management performance.  We conducted a management strategy evaluation to determine effects of assessment frequency and data lag on a range of performance metrics.  Assessment frequency ranged from annual assessments to assessments every fifth year, and data lag (time between last year of data and implementation of regulations) ranged between zero and two years.  Management in the model was based on the Mid-Atlantic control rule and the species life history followed Summer Flounder Paralichthys dentatus.  Assessment frequency and data lag had a substantial effect on the probability of overfishing, but little effect (less than 1% difference, on average) on the average catch or spawning stock biomass throughout scenarios with highly accurate stock assessments. Overfishing increased as data lag increased and assessment frequency decreased. Data lag had a larger effect on probability of overfishing than assessment frequency.   The variability in catch decreased with decreasing assessment frequency and data lag.