"developing alternatives to the use of cereal in animal feed, such as by recycling waste and using fish discards, could sustain the energy demand for the entire projected population growth of over 3 billion people and a 50% increase in aquaculture."
Nellemann, C., MacDevette, M., Manders, T., Eickhout, B., Svihus, B., Prins, A. G., Kaltenborn, B. P. (Eds). February 2009. "The environmental food crisis – The environment’s role in averting future food crises. A UNEP rapid response assessment." United Nations Environment Programme, GRID-Arendal, http://www.grida.no/files/publications/FoodCrisis_lores.pdf