Exploratory analysis of the comparative environmental costs of shrimp farming and rice farming in coastal areas

摘要

In order to explore the possibility of using Material Flow Analysis (MFA) to evaluate comparatively the environmental cost of shrimp farming and rice farming in coastal areas, this exploratory report provides an overview of the different shrimp and rice farming systems currently use worldwide. Then, the most important environmental issues surrounding each system are presented in terms of material flows. Whilst the authors recognised that a comprehensive analysis of the rice or shrimp farming sectorsshould include the whole production chain, in this report the system boundary is the farm enterprise. The report shows that it is possible to adapt MFA methodology to provide quantitative data on environmentally relevant flows, but this in itself does not provide a measure of the impact of these flows on the environment. There are two inherent weaknesses of the method. Firstly, it is oriented towards material inputs and considers only a limited number of emissions. Secondly, it depends upon the notion that the resultant impact of all inputs and outputs can be deduced from their aggregate mass. This ignores obvious differences in the environmental impact of different materials. In order to make any meaningful comparison between shrimp and rice production systems there is a need to modify MFA methodology to allow for consideration of disaggregated data on environmentally relevant flows.