Environmental Engineering Reference
In-Depth Information
Table 3.5
Energy intensity of selected fisheries and aquaculture practices expressed as percentage of
energy return on the investment (EROI %) and as the ratio of energy input to protein energy output.
Species, method (Location)
EROI (%)
Energy input/protein
energy output (kJ/kJ)
Fisheries*
Herring/mackerel, Purse seine (NE Pacific)
56
1.8:1
Herring, Purse seine (NE Pacific)
36
2.8:1
Redfish spp., Trawl (N. Atlantic)
11
9.1:1
Salmon spp., Gillnet (NE Pacific)
6.8
14.7:1
Shrimp, Trawl (N. Atlantic)
5.8
17.2:1
Swordfish/tuna, Longline (NW Atlantic)
4.2
23.8:1
Norway lobster, Trawl (NE Atlantic)
2.6
38.5:1
Tuna/billfish, Longline (Pacific)
2.2
45.5:1
Shrimp, Trawl (S.W. Pacific)
1.9
52.6:1
Crab, Trap (NW Pacific)
1.4
71.4:1
Aquaculture
†
Tilapia, extensive pond (Indonesia)
13.0
7.7:1
Carp, unspecified culture system (Israel)
8.4
11.9:1
Tilapia, unspecific system (Israel)
6.6
15.2:1
Tilapia, pond culture (Zimbabwe)
6.0
16.7:1
Catfish, intensive pond culture (US)
4.0
25.0:1
Atlantic salmon, intensive cage (Canada)
2.5
40.0:1
Shrimp, semi-intensive culture (Ecuador)
2.5
40.0:1
Tilapia, intensive cage culture (Zimbabwe)
2.5
40.0:1
Atlantic salmon, intensive cage (Sweden)
2.0
50.0:1
Chinook salmon, intensive cage (Canada)
2.0
50.0:1
Sea bass, intensive culture (Thailand)
1.5
66.7:1
Shrimp, intensive culture (Thailand)
1.4
71.4:1
Data adapted from Tyedmers, 2004(*), with permission from Elsevier and Tyedmers et al., 2005 (
†
).
technique normally do not survive. Even when the dead bycatch serves as food for other fish,
it actually impacts the ecological balance of aquatic communities with unpredictable conse-
quences (Petruny-Parker et al., 2003).
Food ingredients and additives
Food ingredients are categorized as acidulants, antioxidants, chelating agents, colors, sweet-
eners, emulsifiers, fats and oils, flavors, flours, gums, preservatives, spices, starch, non-
nutritive sweeteners, and vitamins. Other substances that are not added for their nutritional
value but to improve the food product, or its processing, are considered food additives or
processing aids. These include anticaking agents, bleaching agents, flour treatment agents,
humectants, propellants, and thickeners.
Food ingredients and additives are as diverse as the background they come from. Some of
them, such as flours and oils, are from dedicated crops, others are extracted from by-products
of certain industries, for instance gelatin from animal skins and bones or tartaric acid from the
wine industry. Many ingredients and additives are the product of synthesis, for instance colors
and preservatives, and others are obtained by fermentation, such as some organic acids (Table
3.6). It is beyond the purpose of this topic to analyze the environmental impact during the
production of every food ingredient and additive; therefore, three cases will be presented to
exemplify the ramifications of the impact during the production of substances made though
synthesis, transformation of crops, and fermentation.
