Increasing pressure on freshwater resources due to terrestrial feed ingredients for aquaculture production

Abstract

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 production-weighted 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.

Farm water productivity in broiler production: case studies in Brazil

“…The bandwidth of corn produced in the Brazilian states investigated was 1.34e1.93 kg DM m À3 W inputfeed. Feed production differs considerably from one country to the other or within countries, depending on the producer's practice, feed ingredient availability, financial status of the farmers, and the farming system (Pahlow et al, 2015;Miguel et al, 2015). Soy from Mato Grosso had the highest CWP of 0.99 kg DM m À3 W input-feed because of the shorter soy vegetation period in this state compared with the other two states.…”

Metodología para la medición de la huella hídrica en la producción de tilapia, cachama y trucha: estudios de caso para el Valle del Cauca (Colombia)

“…The duration of seed and fattening stages was multiplied by the WF of fish food production. For tilapia and trout it was taken from Pahlow et al (13), and for cachama the value used was the same as for tilapia since they consume the same food (Table 2).…”

“…The WF e is generated in the production of the electric energy consumed during the production process, and depends on the generation technology used (12). The WF cf is the volume of water consumed in the production of the concentrated feed, which is different for each species (13). The WF h is generated in the production of the eggs, larvae or fingerlings.…”

Nutritional Value of Macrobrachium rosenbergii Prawns Fed on Extruded Feeds Enriched with Linseed and Whey Proteins

“…Replacement of fish meal with alternative sources of proteins from terrestrial animals or plants has been encouraged [6]. Additionally, the use of wild fish in the form of fish meal and fish oil as inputs for aquaculture feeds, relies on marine species that are renewable, but often overexploited for human use [7]. Many studies raise questions about the sustainability of the various alternatives for aquatic feed ingredients.…”

“…Fish meal and fish oil are limited. Fish oil may in the future be a scarcer commodity than fish meal for use in aqua feeds [7,8].…”