| "Trash Fish" is a broadly used term for fish species that by virtue of their
small size or low consumer preference have little or no commercial value. The
use of the term "trash fish" varies among States and fisheries and can also
change both seasonally and with location. One category of trash fish are
those not used for human consumption (either landed or discarded at sea).
Those that are landed are often small fish that are targeted for processing
into fish/animal meal, for example Japanese anchovy and chub mackerel or fish
that have become damaged because of rough handling or due to lack of ice or
on-board freezing facilities. The other category is low-value fish used for
human consumption. The huge number of small-scale fisheries in the Asia-Pacific
region generates a large quantity of this type of trash fish, much of which is
consumed or utilized locally as part of household food security, artisanal
processing or for small-scale rural aquaculture and livestock raising.
Utilization may be extremely efficient with almost no wastage and a lot
being converted through drying, fermenting and salting into a wide range of
human food products. In countries such as Bangladesh, almost all fish caught
is consumed.
The issues relating to the different types of trash fish are diverse though intertwined.
One major issue for the region is the increasing demand for trash fish for aquaculture
and other animal feeds. Recognizing the potential effects of declines in marine capture
fisheries, many governments have turned to aquaculture as a means to increase fish
supply, provide employment and generate foreign income. On the one hand, aquaculture
development can be seen as a viable option to utilize trash fish yet, on the other
hand, it is putting increasing pressure on the already over-exploited fish stocks
in the region. Over the last decade, the price of trash fish has risen considerably,
and is predicted to increase over the next few years due to increased demand for fish
meal and fish oil to meet market demands for aquaculture of carnivorous fish (as well
as a source of affordable food). Declining stocks of many trash fish species such as
Japanese anchovy, chub mackerel and filefish will aggravate the situation. Given that
aquaculture is predicted to grow while capture fisheries remains stable, it will be
difficult to meet the demand for trash fish.
Direct feeding of trash fish occurs for some cultured species such as grouper and
mud crabs. They are also used as supplemental feeds for other species such as tilapia,
prawns and milkfish. Trash fish are also being increasingly used as the raw ingredient
in local production of fish meal and fish oil in Asia and the Pacific. The feed
milling industry is a major sector in many States of the region with a large number
of feed mill factories spread across many States. They produce large quantities of
aquaculture, poultry and livestock feeds.
Yet another issue relates to fish landed by larger industrial vessels. These fish
are typically landed at a single point (port) and are typically in a poor state of
preservation or severely damaged from the capture method. Utilization of this fish
is either through conversion into fish meal or direct use for livestock or aquaculture
in the general vicinity of the landing site. The question is whether better post-harvest
handling and processing will yield a better return for this limited resource.
Another separate but related issue is the capture of juvenile fish of potentially
important commercial species (so-called growth over fishing). Trash fish currently
constitute about 60 percent of the total trawl catch from the Gulf of Thailand and
between 18 and 32 percent of trash fish are juveniles of commercially important fish
species. Given a chance to grow to a larger size, these species would provide many
more benefits in terms of production, but even more importantly in terms of value.
|