Use of wild fish in aquaculture and its effects on income and food for the poor 387
5.1.3 Bycatches: a source of fisheries decline that will impact the poor?
All reports seem to show^25 that often a very large part of the bycatch – be it quantified
as trash fish or as low-value foodfish – contains a large share of juveniles of commercial
species. This will negatively impact commercial fisheries, and beyond a certain point,
may even threaten the sustainability of the species. However, in respect of the question
“does the use of bycatch as aquaculture feed lead to unsustainable fisheries?”, the
answer is probably “no” in most situations. There are two reasons.
First, although fishers in Asia have come to see more of an economic role for
bycatch and have modified their fishing practices accordingly, bycatch is still a
secondary motivation. Fishers will add something to their earnings by landing and
selling bycatch, but most income comes from the sale of the fish at which the fishery
was aimed (e.g. shrimp in trawl fisheries for shrimp). So if fishers were prohibited from
landing and selling bycatch (thus being obliged to discard all of it), such a rule would
somewhat reduce the fishing effort, but probably not for long. Therefore, in the wider
context of sustainable fisheries, the use of bycatch as aquaculture feed seems to be a
non-issue, and it is unlikely that fishery managers in the future will be able to count
on a “bycatch for aquaculture prohibition” as an effective tool in the struggle against
unsustainable fisheries^26.
The second reason is that with the exception of China, Thailand and Viet Nam,
aquaculture feed, direct or indirect, is not a dominating use for bycatch. In the rest of
Asia and elsewhere, bycatch is mostly used either as human food, as feed for livestock
and poultry or discarded.
Again, to be clear, fisheries that are characterized by large volumes of bycatch are
also mostly unsustainable; and unless remedied, this may cause a decline of the aquatic
resource base, which most likely in the end will impact negatively on society, including
the poor and undernourished. But, this scenario is not caused by aquaculture, and,
therefore, modifications of aquaculture practices will not contribute to a brighter
future for world marine fisheries in the sense that they would result in sustainable
management of bycatches.
5.1.4 Country notes
China
China reports that large quantities of low-value/trash fish are used in aquaculture. The
practice had been growing in parallel with the growth in aquaculture, and lately some
2.8 to 2.9 million tonnes were reportedly fed annually, mostly to marine finfish. During
this period, market prices for low-value fresh fish increased and poor sections of the
community had seen a fall in their possibilities to consume fish (De Silva and Turchini,
2009).
The proportion of undernourished in the Chinese population has fallen and was
recorded at 9 percent in the period 2003–2005 (FAO, 2008a). This means, however, that
there were still about 125 million undernourished in the country. In the same period,
per capita supplies of fish^27 reached 25.8 kg, providing some 6 g of animal protein
per person per day. However, the Chinese diet is relatively rich in animal proteins
(21 percent of energy comes from animal proteins), and the contribution of fish to
animal protein supply has fallen and was below 20 percent in 2003 (Laurenti, 2007). If
fish used as aquaculture feed in China had been supplied locally as human food, annual
(^25) For examples, see Salagrama (1998) and Ahamad (2005).
(^26) Management of bycatch will probably continue to focus on the “supply”, i.e. the volume of bycatch
caught, accepting that the costs associated with any management of the use of bycatch are prohibitive.
Therefore, efforts will continue to develop technological inventions in the design and use of fishing
gear, but there will also be increasing use of economic incentives and various command and control
strategies.
(^27) Live-weight equivalent.