Environmental comparison of intensive and integrated agriculture–aquaculture systems for striped catfish production in the Mekong Delta, Vietnam, based on two existing case studies using life cycle assessment

Abstract

Vietnam is the largest producer for the export of striped catfish. Traditionally striped catfish production in the Mekong Delta took place in integrated agriculture–aquaculture systems, but has shifted recently to intensive systems to meet increasing export demands. A recent study quantified the environmental impact of intensive striped catfish production in Vietnam. Another did the same for integrated systems. Both studies used life cycle assessment, covered similar environmental impact categories, and were roughly matched in the production stages included. However, an environmental comparison of both systems has not been made so far. The objective of this paper is to make a comparative life cycle assessment of striped catfish production in intensive and integrated systems. The comparison was based on existing life cycle assessments on these systems, but their methodological choices and data had to be aligned. The results show that striped catfish production in intensive systems contributes considerably more to seven of the nine assessed impact categories (global warming, ozone depletion, acidification, eutrophication, photochemical oxidation, human toxicity, freshwater ecotoxicity, marine aquatic ecotoxicity, fossil depletion). Only contributions to eutrophication and freshwater ecotoxicity were higher for the integrated systems than for the intensive systems. In both systems, grow‐out fish farming contributes most to eutrophication and freshwater ecotoxicity, whereas feed production contributes most to all other impact categories. The environmental performance of integrated striped catfish production is convincingly better in most impact categories. This raises questions about whether (elements of) these systems can be used to mitigate the environmental impact of intensive striped catfish production.

Life cycle assessments of aquaculture systems: a critical review of reported findings with recommendations for policy and system development

“…The reduced use of feed is the main source of environmental impact reduction (Kluts et al . ). An exception remains with aquatic eutrophication impacts, which turn out to be higher for the integrated systems if the input of natural fertilizer (usually manure) is not optimized.…”

“…In contrast, other studies showed polyculture systems to have lower environmental impacts thanks to their potential for species complementarity (Kluts et al . ; Mungkung et al . ; Medeiros et al .…”

“…These cause a higher nutrient discharge to rivers during water replacement (Kluts et al . ), although this excess of nutrients has been reported to be recyclable to limit the high aquatic eutrophication (Henriksson et al . ).…”

LCA of aquaculture systems: methodological issues and potential improvements

“…As evidenced in the sensitivity analyses of numerous LCA studies included in the current review (e.g. Winther et al 2009;Kluts et al 2012;Wilfart et al 2013;Aubin et al 2015;Jonell and Henriksson 2015;McGrath et al 2015;Nhu et al 2016;Medeiros et al 2017), the choice of method to solve process multi-functionality is of great importance for the LCA results.…”

“…decreasing some impacts while increasing others as relevant. For instance, toxicity impacts may be of high relevance in aquaculture systems, as showed by Kluts et al (2012), who found a different ranking in their comparative study for freshwater ecotoxicity than for most of the other impact categories assessed. Other impacts are as relevant.…”