Effect of ration and size heterogeneity on harvest time: Tilapia culture in Yucatan, Mexico

Abstract

Size heterogeneity is a common phenomenon in aquaculture systems and influences final production and economic yield. Among other factors, this variability is determined by ration. These variables directly affect potential returns and therefore influence the recommendations made for optimum aquaculture system management. As part of the search for more profitable culture strategies, a bioeconomic model was developed to analyze the effect of size heterogeneity and ration on optimum harvest time and size, thus creating a new methodological tool. Size dispersion was included using a continuous, size-structured population model incorporating the effect of ration on growth. Theoretical results were applied in a case study of tilapia culture in Yucatan State, Mexico, in which optimum ration levels and harvest times clearly differed between size heterogeneity and homogeneity models. Case study results indicated the use of different recommended ration and harvest management strategies depending on real and/or potential target market. © 2011 Taylor and Francis Group, LLC.