Aquaculture with its environment: Prospects for sustainability

The rapid expansion of intensive one-species aquaculture has generated severe environmental as well as socio-economic problems. A major reason is that Western-oriented aquaculture has been managed as an isolated part of its supporting environment. In this paper, the authors compare the use of industrial energy for various aquaculture, fisheries and agriculture systems and analyze the connection between resource use, methods of culturing and environmental impacts. The characteristics of one-species aquaculture, such as intensive throughput-based salmon cage-farming and shrimp pond-farming, are found to be similar to those of stressed ecosystems. Among these characteristics are a very inefficient resource use and generation of by-products that are stored or exported. Because of the problems with these monocultures, there is a great need for Western-oriented aquaculture to redirect the industry's present behavior towards a path of synergy between development and environment. A challenge is to find ecological economic ways to integrate culturing activities in coastal areas. Based on principles of ecological engineering, Chinese integrated systems are synthesized, intensive mangrove-destructing shrimp farming is opposed to integrated shrimp farming, and how a coastal culturing system of seaweeds, mussels and salmon could be developed is suggested. Such systems aim at increased efficiency, reduced resource use, avoidance of chemicals and medicals, less waste generation and the recycling of nutrients and materials. The authors conclude that the more a cultivation system recognizes and mimics natural ecosystem functions the less resource inputs are required and the less environmental effects can be expected. A successful aquaculture system does not have wastes, only by-products, to be used as positive contributors to the surrounding ecosystems and the economy.