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By using discards, waste and other post-harvest losses, the sup-
ply of animal and fish feed can be increased and be sustained
without expanding current production, simply by increasing
energy efficiency and conservation in the food supply chain.
There has been surprisingly little focus on salvaging food al-
ready harvested or produced. An important question centers
around the percentage of food discarded or lost during har-
vesting, processing, transport and distribution as well as at the
point of final sale to consumers. Reducing such losses is likely
to be among the most sustainable alternatives for increasing
food availability.
FOOD – OR FEED – FROM WASTE
Discarded fish from marine fisheries is the single largest pro-
portion lost of any food source produced or harvested from the
wild. The proportion is particularly high for shrimp bottom
trawl fisheries. Mortality among discarded fish is not adequate-
ly known, but has, for some species, been estimated to be as
high as 70–80%, perhaps higher (Bettoli and Scholten, 2006;
Broadhurst
et al
., 2006). Discarded fish alone amounts to as
much as 30 million tonnes, compared to total landings of 100–
130 tonnes/year. Feed for aquaculture is a major bottleneck, as
there are limitations to the available oil and fish for aquacul-
ture feed (FAO, 2008). A collapse in marine ecosystems would
therefore have a direct impact on the prices of aquaculture
Increasing food supply by reducing food waste
It may be prudent to investigate production and distribution
processes and consumption patterns to determine food energy
efficiency and the potential food supply, and not merely uncriti-
cally increase food production. The efforts to produce food of the
highest quality for sale in many countries are often lost simply be-
cause the food is thrown away. This reaches up to 30–40% of the
food that is produced, processed, transported, sold and taken
home by consumers in the UK and USA (Vidal, 2005). Meeting
the future global demand for food needs to include enhancing ef-
ficiencies of existing production areas and processes, converting
wasted food to animal feed and restoring the ecosystems that
underpin our ability to feed ourselves.
Food waste is also water waste, as large quantities of water are
used to produce the lost food. Undoubtedly, agricultural and food
production losses are particularly high between field and market
in developing countries, and wastage (i.e., excess caloric intake
and obesity) is highest in the more industrialized nations. The
loss of, or reduction in other primary ecosystem services (e.g.,
soil structure and fertility; biodiversity, particularly pollinator spe-
cies; and genetic diversity for future agriculture improvements)
and the production of greenhouse gases (notably methane) by
decomposition of the discarded food, are just as important to
long-term agricultural sustainability the world over.
Wasting food is not only an inefficient use of ecosystem servic-
es and of the fossil fuel-based resources that go into produc-
ing them, but also a significant contributor to global warming
once in landfills. In the USA, organic waste is the second highest
component of landfills, which are the largest source of methane
emissions. In the UK, animal digestive processes and manures
release close to 40% its methane emissions (Bloom, 2007).
Agriculture’s contribution to climate change must therefore be
considered in the call to increase global food production.
When taken together, post-harvest losses and the wastage of
food by both the food industry and consumers call for a con-
certed effort in raising awareness of the costs to the environ-
ment of the inefficient use of nature’s resources. Changing the
perception of waste as something that needs to be disposed of,
to one of waste as a commodity with economic and renewable
energy value in the agricultural and food production industries,
should be encouraged. Governments can provide support and
an enabling policy environment in terms of awareness raising,
technology innovation and transfer, agricultural extension to
farmers, and support policies that foster managing and recy-
cling of agricultural and food production waste into animal feed.
They could also promote policies that take account of the value
of ecosystem services, to ensure that ecological needs are also
provided for, such as sufficient water in an aquatic nature reserve
needed to maintain its proper functioning.