The rising share of aquaculture in supplying seafood changes the mixture of species in the world's market, because capture fisheries target carnivorous species whereas aquaculture focuses on species that are lower in the food chain. Trophic level correlates with production volume (tons/yr) and with unit value (US$/ton) in aquaculture but not in capture fisheries (FAO's fisheries data). Apparently, sustainability and economics in aquaculture both depend on ecological efficiency, i.e., the use of resources and the production of waste. Species feeding low in the food chain use efficiently the natural resources. Each level up the food chain inflates costs related to the use of resources, the production of waste and the maintenance of water quality. This effect has further repercussions on the economics of aquaculture: (1) cost influences profit and unit price, and (2) price influences demand and market share. The overall ecological efficiency, sustainability and economics of culturing carnivorous fish are improved by growing them in an ecological balance with species from low trophic levels in integrated multi-trophic aquaculture.
Bibliographical noteFunding Information:
The authors thank Z. Dubinsky, J. J. Lee, H. Rosenthal, T. Samocha, M. Troell, P. Trujillio and C. F. Wurmann-Gotfrit for valuable discussions and comments on the ideas that resulted in this article. We thank S. Herrick, M. D. Krom, M. de Wit and several anonymous reviewers for valuable contributions to the revision. Support was provided by the Israeli Ministry for National Infrastructures (AN) and by the Portuguese Foundation for Science and Technology (AMN). The article is based on three talks, presented by the principle author in the 8th International Marine Biotechnology Conference (IMBC), 2007, Eilat, Israel, Aquaculture Europe 2008, Krakow, Poland and Aquaculture 2010 – ‘‘Sustainable = Profitable’’, San Diego, California, USA. The revised manuscript was prepared while the principle author was on sabbatical with B. G. Mitchell at the Integrative Oceanography Division, Scripps Institution of Oceanography, University of California San Diego.
- ecological efficiency
- production costs
- sustainable aquaculture
- trophic level
ASJC Scopus subject areas
- Geography, Planning and Development
- Aquatic Science