38 Fish as feed inputs for aquaculture – Practices, sustainability and implications
6.1.3 Non-target bycatch or trimmings that are utilized for fishmeal
A number of food-fish species are also used for reduction to fishmeal and fish oil,
either whole fish when market conditions make reduction an economically preferable
alternative or trimmings from processing waste.
Stocks of Atlantic herring (Clupea harengus harengus) are improving and support a
number of economically important fisheries. The majority of herring catches are used
as either fresh or frozen whole fish. The EU-controlled herring fisheries (west of the
United Kingdom, North Sea, Skagerrak and Kattegat) must offer fish of food grade for
human consumption, and fish can only be sent for reduction if they cannot be sold in
the market for human consumption. However, all small pelagic fish caught in the Baltic
Sea can be offered as feed grade. The proportion of herring processed for fishmeal by
the Atlanto-Scandinavian fisheries has decreased from 68 percent in 2001–2002 to
25 percent in 2004–2005 due to a combination of greater land and sea freezing capacity,
as well as strengthening prices for the frozen whole product for human consumption.
The Western European catch of sprat (Spratus spratus) has largely been used for
fishmeal, but it is a popular foodfish in Eastern European Baltic states. However, with
the increased awareness of dioxin contamination of oily fish in the Baltic Sea, it may be
that the demand for fish for human consumption will decrease and a greater proportion
of sprat will be used for reduction (FAO, 2005b). There is the possibility that the
countries of Eastern Europe will increase the use of the low-value feedfish from the
cleaner waters of the North Atlantic Ocean for human consumption. However, this
potential is likely to be constrained by the continued low demand for low-value fish
from this region. In 1985, the regional annual consumption of low-value fish^8 was 2.5
million tonnes but dropped to 150 000 tonnes by 1997 and is predicted to increase not
more than 161 000 tonnes per annum by 2020 (Delgado et al., 2002).
The demand for Antarctic krill is likely to increase due to its excellent value
as a nutrient source for farmed fish and crustaceans (i.e. protein, energy, essential
amino acids). Other outstanding properties of krill are their natural pigment content
(particularly appropriate for salmon farming), palatability, low content of pollutants,
and the likely improvement of larval fish survival. These attributes make krill meal a
more attractive feed than potential competitors such as squid meal, clam meal, artemia
soluble and fish soluble (Sclabos, 2003). The relatively high prize of krill products may
however limit their use in aquafeed in general.
In summary, the use of the main feed-fish species for direct human consumption
is driven by market and other economic factors rather than by technical or product
development constraints. As a result, there is unlikely to be any dramatic change over
the medium term in the proportion of feed-fish species being used directly as food.
However, this depends upon a number of extrinsic factors such as the availability and
price of other feed-protein commodities such as soya meal.6.2 Comparative analysis of the use of feedfish in aquafeeds versus for
human consumption
As the section above indicates, there are few alternative uses of feedfish for the main
feed fisheries supplying fishmeal production in Europe that are not already occurring.
In European feed fisheries, a more fundamental question is whether it would be
more ecologically efficient if these feed-fish stocks – which are often prey items for
commercial fish species and an integral mid-level component of the food chain in many
European seas – are left in the sea. Essentially, is it more effective to harvest low-trophic-
level species in industrial fisheries and convert the biomass obtained to fish protein for
human consumption via aquaculture systems, or is it better to leave low-trophic-level(^8) According to the International Standard Statistical Classification of Aquatic Animals and
Plants(ISSCAAP), low-value fish include herrings, sardines, anchovies and mackerels.