A Review Of Alternative Pond Harvesting Schedules For Male And Female Redclaw Crayfish Cherax Quadricarinatus, Reared In Intensive Monosex Commercial Conditions: A Stochastic Bioeconomic Approach

We use a bioeconomic model to analyse two alternative harvesting schedules for male and female redclaw: simultaneous (same day) harvests of ponds for each sex and harvesting ponds independently for each sex (different days). The results show that, for simultaneous harvests, best results are obtained after 120 days of cultivation yielding, with 95% confidence, a mean net revenue (NR) of 26,820 USD$ ha(-1) and mean benefit-cost ratio (B/C) of 3.08. For independent harvests, best results are obtained by harvesting males after 109 (NR) and 97 (B/C) days, and females after 120 (NR) and 107 (B/C) days. At these optimum harvesting times, with 95 % confidence, expected mean NR for males was 30560 USD$ ha(-1) and mean B/C was 3.56; while for females NR was 23,620 USD$ ha(-1) and B/C was 2.92. Results show that using independent harvests maximizes benefits. Better economic performance and statistical confidence were observed for males. The dynamics of commercial grade categories is the most important factor influencing the stochastic variability of NR, while the cost of production of pre-adults is negligible, indicating the reliability of the cultivation technology for the nursery stage. Bioeconomic modelling provides an objective framework for farming practices evaluation and avenues for improvement. Monosex redclaw crayfish culture is environmentally sustainable, with a consistent production technology that is economically viable. With increasing world demand, it should be considered a strong candidate species for diversification.