+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on LinkedInFollow on LinkedIn

+ Translate

Sustainability assessment of salmonid feed using energy, classical exergy and eco-exergy analysis

Sustainability assessment of salmonid feed using energy, classical exergy and eco-exergy analysis

Ecological Indicators 34: 277-289

Reduction of the environmental impact of feed products is of paramount importance for salmon farming. This article explores the potential to compare three thermodynamically based ecological indicators. The environmental impact of partial replacement of fish meal (FM) and fish oil with alternative ingredients was investigated using energy, classical exergy and eco-exergy analysis. Seven hypothetical feeds were formulated: one with high levels of FM and fish oil, four feeds based on plant ingredients, one containing krill meal, and one based on algae-derived products. Analysis included cultivation of crops and algae, fishing for fish and krill, industrial processing of these ingredients and production of complete fish feed. Because most harvested products are refined in multiple product outputs that have good value to society, two scenarios were compared. In the base case scenario, no allocation of co-products was used and all the environmental costs were ascribed to one specific co-product. Co-product allocation by mass was used in the second scenario; this is considered to be the preferred scenario because it accurately reflects the individual contributions of the co-products to the environmental impact of the feed products. For this scenario, the total energy consumption for a fish-based diet was 14,500MJ, which was similar to a krill diet (15,600MJ), about 15 31% higher than plant-based diets, and 9% higher than an algae diet. Substituting FM and fish oil with alternative ingredients resulted in minor changes in total classical exergy degradation (2 16% difference). The calculations based on energy only consider the energy conservation based on the First Law of Thermodynamics, whereas those based on classical exergy also takes the Second Law of Thermodynamics into account; energy that can do work is distinguished from energy that is lost as heat to the environment. The calculations based on eco-exergy consider the total loss of work energy in the environment including the work energy associated with the information embodied in the genomes of organisms. The diet based on fishery-derived ingredients was the highest total work energy consumer compared with plant-based diets (24 30% greater), the diet containing krill meal (25% greater), and the algae diet (four times higher). Thus, reducing FM and fish oil levels in fish feed can contribute significantly to more sustainable aquaculture. In particular, algae-derived products in aquafeeds could drastically decrease environmental costs in the future.

(PDF emailed within 0-6 h: $19.90)

Accession: 036935242

Download citation: RISBibTeXText

DOI: 10.1016/j.ecolind.2013.05.017

Related references

Exergy, exergy ratio, and specific exergy as measures of ecosystem health of the Nakdong River. Korean Journal of Limnology. December; 324: 281-287 Serial Number 88, 1999

Exergy analysis in the assessment of the sustainability of waste gas treatment systems. Science of the Total Environment 273(1-3): 41-52, 12 June, 2001

Anthropogenic and natural exergy losses (exergy balance of the Earth's surface and atmosphere). Energy Oxford 28(11): 1047-1054, 2003

Application of exergy and specific exergy as ecological indicators of coastal areas. Aquatic Ecosystem Health and Management, 33: 419-430, 2000

Exergy and structural exergy as ecological indicators for the development state of the Lake Chaohu ecosystem. Ecological Modelling. 99(1): 41-49, 1997

Use of exergy and structural exergy as ecological indicators for the development state of homogeneous lake ecosystems. Annals of the New York Academy of Sciences. June 30; 879: 406-410, 1999

Exergy and extended exergy accounting of very large complex systems with an application to the province of Siena, Italy. Journal of Environmental Management 86(2): 372-382, 2006

Description of aquatic ecosystem's development by eco-exergy and exergy destruction. Ecological Modelling 204(1-2): 22-28, 2007

System-level responses of lake ecosystems to chemical stresses using exergy and structural exergy as ecological indicators. Chemosphere uary; 46(2): 173-185, 2002

Exergy analysis: A tool to study the sustainability of food supply chains. Food Research International 39(1): 1-11, 2006

Exergy analysis in the asessment of the sustainability of the biofilter system, compared with other waste gas treatment systems. Mededelingen Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen Universiteit Gent 65(3A): 71-74, 2000

Thermodynamic oriented ecological indicators Application of Eco-Exergy and Specific Eco-Exergy in capturing environmental changes between disturbed and non-disturbed tropical reservoirs. Ecological Indicators 24: 543-551, 2013

Use of thermodynamic indices as ecological indicators of the development state of lake ecosystems 2. Exergy and specific exergy indices. Ecological Modelling 159(2-3): 223-238, 2003

Energy and exergy utilization assessment of the Greek transport sector. Resources Conservation and Recycling 52(5): 700-706, 2008

Exergy for better environment and sustainability. Environment, Development and Sustainability 11(5): 971-988, 2009