INRA, UMR1069, Sol Agro et hydrosystème Spatialisation, 65 rue de Saint Brieuc, CS 84215, F-35042 Rennes, France.
J Environ Manage. 2013 May 30;121:96-109. doi: 10.1016/j.jenvman.2013.01.031. Epub 2013 Mar 24.
An integrated approach is required to optimise fish farming systems by maximising output while minimising their negative environmental impacts. We developed a holistic approach to assess the environmental performances by combining two methods based on energetic and physical flow analysis. Life Cycle Assessment (LCA) is a normalised method that estimates resource use and potential impacts throughout a product's life cycle. Emergy Accounting (EA) refers the amount of energy directly or indirectly required by a product or a service. The combination of these two methods was used to evaluate the environmental impacts of three contrasting fish-farming systems: a farm producing salmon in a recirculating system (RSF), a semi-extensive polyculture pond (PF1) and an extensive polyculture pond (PF2). The RSF system, with a low feed-conversion ratio (FCR = 0.95), had lower environmental impacts per tonne of live fish produced than did the two pond farms, when the effects on climate change, acidification, total cumulative energy demand, land competition and water dependence were considered. However, RSF was clearly disconnected from the surrounding environment and depended highly on external resources (e.g. nutrients, energy). Ponds adequately incorporated renewable natural resources but had higher environmental impacts due to incomplete use of external inputs. This study highlighted key factors necessary for the successful ecological intensification of fish farming, i.e., minimise external inputs, lower the FCR, and increase the use of renewable resources from the surrounding environment. The combination of LCA and EA seems to be a practical approach to address the complexity of optimising biophysical efficiency in aquaculture systems.
需要采取综合方法来优化水产养殖系统，在最大程度提高产量的同时，将其对环境的负面影响降至最低。我们开发了一种整体方法，通过结合基于能量和物质流分析的两种方法来评估环境绩效。生命周期评估 (LCA) 是一种标准化方法，可估算产品整个生命周期内的资源利用和潜在影响。能值分析 (EA) 是指产品或服务直接或间接需要的能量数量。这两种方法的结合用于评估三种不同水产养殖系统的环境影响：在循环系统中生产三文鱼的养殖场 (RSF)、半集约化多营养鱼塘 (PF1) 和集约化多营养鱼塘 (PF2)。RSF 系统的饲料转化率 (FCR = 0.95) 较低，与两个池塘养殖场相比，每生产一吨活鱼的环境影响较小，当考虑到气候变化、酸化、总累积能源需求、土地竞争和对水的依赖的影响时更是如此。然而，RSF 与周围环境明显脱节，高度依赖外部资源（例如养分、能源）。池塘充分利用可再生自然资源，但由于对外来投入的利用不完全，因此环境影响较大。本研究强调了成功实现水产养殖生态强化的关键因素，即减少外部投入、降低 FCR 以及增加对周围环境可再生资源的利用。LCA 和 EA 的结合似乎是解决水产养殖系统中生物物理效率优化复杂性的实用方法。
