Chapter 6
Safe and Nutritious Aquaculture Produce:
Benefits and Risks of Alternative
Sustainable Aquafeeds
J. Gordon Bell
1 * and Rune Waagbø
2
Abstract It is estimated that by 2010 >85% of globally available fish oil (FO) and
~50% of fish meal (FM) will be consumed by aquaculture so, it is vital that reliance
on marine raw materials is reduced and that sustainable aquafeeds are developed
using more terrestrial plant products. In addition, levels of persistent organic
pollutants (POPs), principally dioxins/furans and polychlorinated biphenyls
(PCBs), in some European FO may breach new EU limits and prevent their use in
aquafeeds. Current evidence suggests that salmonids can be grown on diets where
100% of the FO is replaced by vegetable oils (VO), and that bass and bream fed
up to 60% VO showed no detrimental effects on growth. However, use of VO can
result in reductions of the n-3 highly unsaturated fatty acids, DHA and EPA, of
between 50% and 65%, although these values can be restored to 70–100% of the
values in fish fed FO by the use of FO-containing finishing diets. Such high levels
of FO replacement can only be used if essential fatty acid levels are maintained
by inclusion of adequate FM levels. Simultaneous reductions in FM and FO will
require considerable care if fish health and welfare, as well as product quality, are
to be maintained. The efficacy of n-3 highly unsaturated fatty acids (HUFA), principally EPA and DHA, in the prevention or modulation of many of the inflammatory
conditions prevalent in the developed world is well established. However, there is
concern that the levels of POPs (dioxins, PCBs and PBDEs), as well as the presence
of toxic metals, (e.g., Pb, As, Cd and Hg), present a potential risk to human health.
The nutrients, as well as contaminants, found in fish flesh are derived largely from
the feed and, thus, farmed fish can be tailored to provide optimal levels of fatty
acids, and selected vitamins and minerals for human consumption.
Keywords Sustainable aquafeeds, vegetable oils, plant proteins, micronutrients,
n-3 fatty acids, organic contaminants
1
Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, Scotland, U.K, Tel. + 44 1786
467997, Fax. + 44 1786 472133, E-mail: g.j.bell@stir.ac.uk
2 National Institute of Nutrition and Seafood Research (NIFES), PO Box 2029, Nordnes,
5817 Bergen, Norway
* Corresponding author
M. Holmer et al. (eds.), Aquaculture in the Ecosystem.
185
© 2008 Springer
Safe and Nutritious Aquaculture Produce:
Benefits and Risks of Alternative
Sustainable Aquafeeds
J. Gordon Bell
1 * and Rune Waagbø
2
Abstract It is estimated that by 2010 >85% of globally available fish oil (FO) and
~50% of fish meal (FM) will be consumed by aquaculture so, it is vital that reliance
on marine raw materials is reduced and that sustainable aquafeeds are developed
using more terrestrial plant products. In addition, levels of persistent organic
pollutants (POPs), principally dioxins/furans and polychlorinated biphenyls
(PCBs), in some European FO may breach new EU limits and prevent their use in
aquafeeds. Current evidence suggests that salmonids can be grown on diets where
100% of the FO is replaced by vegetable oils (VO), and that bass and bream fed
up to 60% VO showed no detrimental effects on growth. However, use of VO can
result in reductions of the n-3 highly unsaturated fatty acids, DHA and EPA, of
between 50% and 65%, although these values can be restored to 70–100% of the
values in fish fed FO by the use of FO-containing finishing diets. Such high levels
of FO replacement can only be used if essential fatty acid levels are maintained
by inclusion of adequate FM levels. Simultaneous reductions in FM and FO will
require considerable care if fish health and welfare, as well as product quality, are
to be maintained. The efficacy of n-3 highly unsaturated fatty acids (HUFA), principally EPA and DHA, in the prevention or modulation of many of the inflammatory
conditions prevalent in the developed world is well established. However, there is
concern that the levels of POPs (dioxins, PCBs and PBDEs), as well as the presence
of toxic metals, (e.g., Pb, As, Cd and Hg), present a potential risk to human health.
The nutrients, as well as contaminants, found in fish flesh are derived largely from
the feed and, thus, farmed fish can be tailored to provide optimal levels of fatty
acids, and selected vitamins and minerals for human consumption.
Keywords Sustainable aquafeeds, vegetable oils, plant proteins, micronutrients,
n-3 fatty acids, organic contaminants
1
Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, Scotland, U.K, Tel. + 44 1786
467997, Fax. + 44 1786 472133, E-mail: g.j.bell@stir.ac.uk
2 National Institute of Nutrition and Seafood Research (NIFES), PO Box 2029, Nordnes,
5817 Bergen, Norway
* Corresponding author
M. Holmer et al. (eds.), Aquaculture in the Ecosystem.
185
© 2008 Springer