As aquaculture becomes more important for feeding the growing world population, so too do the required natural
resources needed to produce aquaculture feed. While there is potential to replace fish meal and fish oil with terrestrial
feed ingredients, it is important to understand both the positive and negative implications of such a development.
The use of feed with a large proportion of terrestrial feed may reduce the pressure on fisheries to provide
feed for fish, but at the same time it may significantly increase the pressure on freshwater resources, due to water
consumption and pollution in crop production for aquafeed. Here the green, blue and gray water footprint of cultured
fish and crustaceans related to the production of commercial feed for the year 2008 has been determined
for the major farmed species, representing 88% of total fed production. The green, blue and gray productionweighted
average feed water footprints of fish and crustaceans fed commercial aquafeed are estimated at
1629 m3
/t, 179 m3
/t and 166 m3
/t, respectively. The estimated global total water footprint of commercial aquafeed
was 31–35 km3 in 2008. The top five contributors to the total water footprint of commercial feed are Nile tilapia,
Grass carp, Whiteleg shrimp, Common carp and Atlantic salmon, which together have a water footprint of
18.2 km3
. An analysis of alternative diets revealed that the replacement of fish meal and fish oil with terrestrial
feed ingredients may further increase pressure on freshwater resources. At the same time economic consumptive
water productivity may be reduced, especially for carnivorous species. The results of the present study show that,
for the aquaculture sector to grow sustainably, freshwater consumption and pollution due to aquafeed need to be
taken into account.