Evaluating partial harvesting strategies for whiteleg shrimp Litopenaeus (Penaeus) vannamei semi-intensive commercial production: profitability, uncertainty, and economic risk

Abstract

A bioeconomic model and Monte Carlo simulation were used to analyze alternative management scenarios of partial harvesting schedules in semi-intensive shrimp (Litopenaeus vannamei) farming, emphasizing profitability, uncertainty, and economic risk. The schedules, including 1, 2, and 3 partial harvests, were studied considering two management scenarios (worst and best). Management improved by using high stocking density and reducing the rearing period. Higher profitability was calculated for Schedule 3 (US$ 6699 ha-1) in the best scenario, while Schedule 1 yielded the worst result even under the best scenario (US$ 2451 ha-1). Uncertainty diminished as management improved, as indicated by lower relative variability of the economic indicators. Higher uncertainty was expected for Schedule 1, while similar uncertainty was estimated for schedules 2 and 3. The highest economic risk was estimated for Schedule 1 in the worst scenario where a single pond would have a 27.9% probability of having economic losses. No losses were expected when using the best scenario for Schedule 3. Calculating the effect of averaging the results of 20 ponds rather than only one pond reduced uncertainty (from 76.9–78.4%) and loss probability (98.5%) in Schedule 1. Null loss probability was calculated for 20 ponds in the rest of the schedules. A sensitivity analysis indicated that the main factors affecting net revenues were final shrimp weight, shrimp prices of large shrimp, mortality rate before the first partial harvest, and rate at which the feed conversion ratio increased throughout the rearing period.