LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

GROUP 1, SESSION A: ANIMAL PRODUCTION SYSTEMS 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
36. Life cycle assessment of integrated fish pond aquaculture of
household farms in sub-Saharan Africa
Thomas Efole Ewoukem 5,* , Joël Aubin 1,2 , Olivier Mikolasek 4 , Michael S. Corson 1,2 , Hayo van der Werf 1,2 ,
Dominique Ombredane 2,3
1 INRA, UMR1069, Soil Agro and hydroSystem, F-35000 Rennes, France, 2 Agrocampus Ouest, F-35000,
Rennes, France, 3 INRA, UMR0985, Ecology and Ecosystem Health, F-35000 Rennes, France, 4 CIRAD F-
34398 Montpellier, France, 5 University of Dschang P.O.Box: 222 Dschang, Cameroon, * Corresponding
author. E-mail: efole_thomas@yahoo.fr
Life Cycle Assessment (LCA) of integrated pond aquaculture of household farms in sub-Saharan Africa was
carried out from 2008-2010 to identify ways to improve the systems and better understand the contribution
of fish-pond systems to regional sustainable development.
A total of 20 polyculture fish ponds corresponding to three types of integrated fishpond system (semiintensive
medium or small; extensive) were chosen after screening household farms with aquacultural activities.
Thus, inland fish-farm production in two contrasting areas of Cameroun was analysed. The fishproduction
system were integrated in the farms with either pig- or crop-production systems. In all farms, fish
production was a polyculture based on tilapia (Oreochromis niloticus) or a tilapia-catfish (Clarias gariepinus)
association. Secondary species often were included depending on the type of fish farm. For example,
Hemichromis fasciatus or the snakehead fish (Parachana obscura) could be included to control tilapia population
size, while common carp (Cyprinus carpio) or Heterotis niloticus could be included (according to
availability) due to their bottom-feeding activity.
LCA was conducted according to the CML2001 method adapted to aquaculture production using economic
allocation (taking manure into account), one tonne of fish as the functional unit, and background data from
Ecoivent. The system boundary included on-farm processes, production of feed and fertiliser, fingerlings,
and transportation at all stages. Dynamics of nitrogen and phosphorus were evaluated using a nutrient massbalance
modelling approach.
With the exception of extensive systems, there was large variability in the magnitude of impacts within each
type of system. The main processes contributing to impacts were fish production, manure fertilisation, and
fry production. Environmental impacts of the semi-intensive systems analysed were high compared to similar
aquatic systems in Brazil. Their low efficiency and the source and origin of their inputs determined the
magnitude of impacts. A water-purification role of extensive systems was also observed. On the other hand,
the amount of human labour, which plays a strong social role sub-Saharan Africa, was higher in all semiintensive
systems.
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