Fish as feed inputs for aquaculture – Practices, sustainability and implications: a global synthesis 35
basis for setting environmental quality benchmarks and monitoring targets for
aquaculture areas.- Joint management of sea, semi-enclosed bay, lake and watershed areas: In
Scotland, the use of Area Management Groups has resulted in greater coordination
among different farming interests within a single waterbody that allows joint
management actions, such as the complete fallowing of sea areas between
aquaculture production cycles. This helps control and reduce the cumulative
impacts of intensive aquaculture, especially in areas with limited flushing rates. - Waste reduction strategies: Perhaps the greatest change in intensive aquaculture
over the last ten years has been the reduction of wastage through better
management and monitoring of feeding. Various approaches have been adopted,
including maximizing the bioavailability of feed components through research and
trialing, as well as better feed delivery management using computer-controlled,
centralized feeding systems. Feeding rates can be further adjusted through the use
of underwater cameras and sensors that detect when feed is passing through cage
systems and not being utilized by the stock, thus invoking a reduction in feeding
rates. - Environmental monitoring: Intermittent monitoring of the benthos and water
column will also provide managers with information on the levels of feed
utilization, wastage and impact from aquaculture systems, especially when
combined with the EQS approach described above.
- CURRENT POTENTIAL ALTERNATIVE USES OF FISH AND OTHER AQUATIC
SPECIES AND THE RELATED MACRO-LEVEL IMPACTS ON FOOD SECURITY AND
POVERTY ALLEVIATION
6.1 Current and alternative uses of feed-fish catches
On the assumption that it is more efficient to consume so-called feedfish directly rather
than via their inclusion as a component of aquafeed (a premise discussed in Section 6.2),
there have been a number of initiatives to develop and market both small pelagic fish
and “trash fish” for direct human consumption.
6.1.1 Increased utilization of the “feed fisheries” to supply feedfish for human
consumption
An increasing proportion of the catch of Chilean jack mackerel and other pelagics,
including the Patagonian grenadier (Macruronus magellanicus) and the chub mackerel
(Scomber japonicus), is being processed for direct human consumption. Despite the fact
that the average price of frozen jack mackerel and fishmeal was similar, the reported
yield from jack mackerel was about 23 percent for meal production and 5–7 percent
for oil production, as compared with 70–75 percent when frozen fish was produced
(Wray, 2001). Clearly, under these circumstances selling the fish for direct human
consumption is much more profitable than reducing it to fishmeal and oil.
The trend toward increased direct human consumption of traditional feed-fish species
(including the use of refined fish oil for direct consumption) is expected to continue in
the long run as fish prices continue to rise; national governments actively encourage the
direct consumption of potential food-grade pelagic fish species (e.g. Chile, SERNAC,
2007; Peru, Chuquin, 2006); and fish harvesting, processing and stabilization methods
improve and consequently fish quality for the consumer improves (Bechtel, 2003;
Gelman et al., 2003). At present, around 58.5 percent of jack mackerel is turned into
fishmeal, with 23 percent canned, 13 percent frozen and the balance used to produce
surimi (Bórquez and Hernández, 2009) (see Box 1).
Similarly, in the case of Peru, the growth in the proportion of the anchoveta harvest
destined for direct human consumption has increased markedly since 2000, despite the
fact that only 27 065 tonnes or 0.32 percent of the total Peruvian anchoveta harvest in