Eco-efficiency assessment of disease-infected shrimp farming in Mexico using environmental impact assessment tools

Mexico ranks second in shrimp (Litopenaeus vannamei) production of in Latin America with significant annual growth, however, during 2011 shrimp production fell by almost 50 % due to the presence of the white spot syndrome virus (WSSV). In this context, a life cycle analysis (LCA) and data envelopment analysis (DEA) were performed on 76 commercial farms severely affected by the presence of WSSV in northwestern Mexico. The application of this combined methodology allowed a detailed quantification of different environmental impact categories. During the presence of WSSV, there was a negative effect on the feed conversion ratio (FCR) (>40 %), higher consumption of seawater (38 %), and energy (38 %). Consequently, operational outputs related to the discharge of nitrogen and phosphorus increased by 60 and 57 %, respectively. Similarly, CO₂ emissions, increased by 38 % relative to a typical year of production. Overall, the main critical points in the impact categories analyzed are related to food (98 %), use of diesel (23 %), and rearing (24 %), dominating pollutants emissions in all categories. Consequently, an improvement scenario was evaluated related to innovation in the formulation of foods supplied with immunostimulants, which confer protection against pathogenic microorganisms. This scenario lead to a reduction environmental impact of about 82 %. The results of this analysis will be a useful resource in the design of mitigation strategies with innovation processes that allow maintaining yields for shrimp producers in this region and at the same time reduce the environmental impacts generated.