Letter to the EditorCommunicating about the emergy ecological footprint for a small fish farm in China

Sustainability evaluation of mariculture is needed for policy decision-making in its development. Zhao et al. (2013) developed the method of emergy ecological footprint to evaluate an offshore small fish farm in the East China Sea. After re-examination of their method, data analysis process and results, three questions are presented (1) what is the nature of this method? (2) How much impact do the recognition and classification of input flows on the results? (3) Do their evaluated results confirm to the real situation of this farm? Further discussions are also made on several main studies about the emergy ecological footprint method. Our results imply: (1) there is a need to improve this method; (2) the input flows should be carefully processed due to their great impacts on the results; (3) the essential data and comparative analysis are needed to support this evaluation.