Fish as feed inputs for aquaculture – Practices, sustainability and implications: a global synthesis 49low-cost fish towards direct human consumption, either directly or more likely, in
some procesed form of (e.g. as a protein mix or a dried, salted or fermented product
like fish sauce). However, the potential is limited due to the difficulties in sorting and
separating low-value fish from other bycatch and preserving them for subsequent
direct consumption.8.1.3 Environmental issues
Environmental issues can be considered from a number of angles. Fundamental are
the status of key forage-fish stocks and the consequences of fishing pressure on their
predators. While such stocks are usually resilient to high exploitation levels, their
robustness can be compromised by wider climatic and other perturbations. With
regards to trash and low-value fish that are mainly caught as bycatch, apart from stock
depletion, implications are the wider biodiversity and ecological impacts resulting from
the removal of such a large and diverse biomass.
A second category of environmental concern is the impact of aquafeed use. Modern
compounded feeds have been developed under increasingly strict environmental
regulations and thus tend to be very efficient in conversion terms, with relatively
little direct impacts from their non-digestible components. However, the net impact is
highly dependent upon the conditions in which they are used and the feeding regime
adopted. Of greater concern is the use of whole fish or farm-made trash-fish slurries
with low FCRs, poor digestibility and high wastage. For this reason, compounded
feeds are preferred for both intensive aquaculture and where there are clusters of farms
taking water from the same source.8.1.4 Food security and livelihood issues
Changing the balance between fish being used for aquafeeds and direct human
consumption has implications for food security^10 at both the local and national levels.
An important factor is whether the primary product (e.g. the fishmeal itself) or the
secondary product (i.e. the fish that result from the aquafeed) becomes available to
local populations at an affordable price. In South America, most small pelagic fish are
either converted into fishmeal or into export-oriented canned and marinated products.
Furthermore, most of the secondary product (e.g. farmed salmon from Chile) is also
exported and only available to the affluent urban populations in the region. There has,
therefore, been an emphasis on developing low-cost food alternatives, especially in Peru
and Chile, to address regional food security needs. For example, the reallocation of
157 300 tonnes (1.8 percent) of the Peruvian anchovy catch from the reduction fishery
to human consumption would be sufficient to raise the Peruvian annual consumption
from 21 to 25 kg per capita.
In Asia, the situation is less clear cut. Most of the trash/low-value fish used for
aquaculture is absorbed by small-scale producers who cannot afford compounded feeds
and thus is an important factor in maintaining their livelihoods. As discussed above,
there is pressure to intensify production and thus increase the use of compounded
feeds. A recent study (Rola and Hasan, 2007) showed contrasting benefits from
intensification – while there was a positive relationship between commercial feeding and
the cost/benefit ratio (CBR) supported by the data from Thailand, the Philippines and
India, data from Bangladesh, China and Viet Nam showed that extensive production
resulted in a higher CBR. This suggests that for many small-scale producers – and
their dependent communities – the use of trash/low-value fish makes sense from an(^10) “All people at all times have both physical and economic access to the basic food they need” (FAO
Committee on World Food Security). Alternate definition: Freedom from hunger. The capability
to produce an adequate amount of food for all consumers at affordable prices (FAO, 2009) (FAO
Fisheries Glossary, accessed on 31 July 2009 (available at http://www.fao.org/fi/glossary/default.asp)..)