Fish farming in the Mediterranean has increasingly shifted from producing fish such as grey mullet, which are herbivores near the bottom of the food chain, to species such as sea bass, which are predators. This ‘farming up’ the food chain requires wild fish to be caught to provide feed. A return to farming fish lower in the food chain would use marine resources more efficiently, a new study says.

Fish farms, and other forms of aquaculture, are seen as a potential solution to meeting increasing global demand for seafood. However, according to recent research, they must reduce their reliance on wild fish for animal feed if current production levels from both aquaculture and wild fisheries are to be maintained.

Urban planning policy has had a powerful influence on the amount of green space in cities, according to a recent UK study. It found that a change in planning policy in 2000 led to a decline in urban green space in nine cities between 2001 and 2006, although the amount of green space in all but one of the cities studied has increased overall since 1991.