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Aquaculture has a high water consumption
Did you know that while water covers 70 % of the earth’s surface, only 2.5 % is freshwater? That 2.5 % can be divided into surface/other freshwater (1.2 %), groundwater (30.9 %) and glaciers/icecaps (68.7 %). It is estimated that by 2050 the demand for this freshwater in food production will be 2.5 to 3.5 times greater than it is today. With agriculture already using an estimated 70 % of freshwater, water usage is clearly an important issue.
How do we define water usage? You may have heard it takes 130 liters of water to make a cup of coffee. How do we calculate these figures and what information do we have on water usage in aquaculture?
When we measure water usage in production, we use the term ‘water footprint’. This refers to the amount of ‘virtual water’ or the water we don’t see used in production. The ‘water footprint’ of a product includes direct and indirect usage of water. Within the ‘water footprint’, water is further defined as ‘green’ (precipitation such as rain), ‘blue’ (surface or groundwater), or ‘gray’.
For aquaculture, direct use of water primarily refers to the water where the fish is raised. At the farm level, the primary indirect usage of water derives from feed ingredients produced in terrestrial agriculture. The direct and indirect water usage in aquaculture varies greatly by production system, species and location. For example, water usage tends to be higher for aquaculture operations in brackish water, where groundwater is used to reduce the salinity, and lowest for marine aquaculture. With regards to feed, the aquafeed global ‘water footprint’ estimate (green and blue water) is roughly two thirds of that for chicken, slightly above half of the equivalent for pork and slightly less than one fifth of the equivalent for beef, making aquaculture a more sustainable agriculture product. &
Responsibly farm-raised fish and seafood can help reduce your overall ‘water footprint’. As a certification scheme that covers agriculture, livestock, flowers and feed as well as aquaculture, GLOBALG.A.P. is sensitive to the importance of responsible water usage and has incorporated responsible water usage practices into its standards. So, when you see the GGN label on a product, you have the additional assurance that water usage has been taken into consideration.
 https://www.imeche.org/docs/default-source/default-document-library/global-food---waste-not-want-not.pdf?sfvrsn=0 p. 3.
 About 18,900 liters of water are needed to produce 1 kg of roasted coffee. For a standard cup of coffee (125 ml) we require 7 grams of roasted coffee, so that a cup of coffee costs 130 liters of water. http://waterfootprint.org/en/resources/interactive-tools/product-gallery/
 J.A. Gephart et al., The ‘seafood gap’ in the food-water nexus literature—issues surrounding freshwater use in seafood production chains, Advances in Water Resources (2017) p. 5.
 Pahlow, M., van Oel, P.R., Mekonnen, M.M., Hoekstra, A.Y., 2015. Increasing pressure on freshwater resources due to terrestrial feed ingredients for aquaculture production. Sci. Total Environ. 356, 847–857.
 See 4 above p. 5.