Download Bitter harvest — rice fields and fish culture

Bitter harvest —
rice fields and fish culture
C. H. Fernando
Almost 50 years ago I saw the imaginative neo-realistic film
called “Bitter Rice.” This controversial film had an additional
meaning for me as my home at that time was next to a large
rice field. However, at the end of the 1940s, when this film was
being made in the rice fields of southern Italy, the rice farmers
actually living there had decided to pay fines rather than raise
carp in their fields as decreed by the government. Perhaps they
already knew that there was a wide chasm between expectation
and reality when it came to farming fish in rice fields.
A Missing Link?
In later years, when I had become a biologist, I frequently
tried to relate the tantalizing dream of raising fish and rice
together in the same wet fields, to provide a complete meal for
the under-nourished people of the world, with the reality of the
checkered history of the successful implementation of that approach anywhere outside China. Was there a missing element,
some key, which could make rice-fish culture profitable, at least
in the tropics and subtropics?
Wild fish had been harvested from rice fields perhaps from
time immemorial, but could some better organized human intervention actually move this practice from hunting to profitable
husbandry of fish in rice fields? Rice paddies are quite complex
ecosystems which go through aquatic, semi-aquatic and terrestrial phases, sometimes with great rapidity. Also, the ancient
practices of cultivation are now replaced by modern agricultural
methods which, in some parts of the world, are highly technical.
Therefore, can the practices of rice production in this new millennium somehow still be blended with the production of fish
for profit at the same time?
A Hasty Judgment
In the nineteenth and twentieth centuries, integrated ricefish farming had been widely promoted in Italy, Russia and
Japan. The inspiration behind this enterprise seems to have
come from China. As China was even then the epicenter of
fish culture, it is not unreasonable to assume that they knew
what they were doing - as they had been raising fish in rice
fields for some 2,000 years. Rice-fish culture was also practiced in India for many centuries, but it was probably less
well developed as it was not that widely known. But the
testing and subsequent abandonment of rice-fish farming in
those three countries (Italy, Russian and Japan) - each with
advanced scientific research establishments - seemed to me an
Sri Lanka. Traditional rice fields colonized naturally by
indigenous fishes during flooding and harvested when the dry
season approaches.
indication that perhaps rice-fish farming could not be sustained
elsewhere other than in China.
Perhaps my judgment then was too hasty, as rice-fish farming is again being heralded as a success in China although, for
some strange reason, it was considered a capitalist enterprise
and forbidden under the Communist regime. Recently there
have been several international meetings in Asia in which ricefish farming has been promoted. But in my considered opinion,
commercially profitable and sustained rice-fish farming in any
credible form has yet to be demonstrated. The only sustained
enterprise for raising aquatic animals for food at a profit with
rice is crayfish farming in the rice paddies of Louisiana in the
USA. The same crayfish species is now raised also in rice paddies in Spain and China.
Much scientific work has been conducted on the ecology of
rice fields, not only in Italy, Russia and Japan, but also in some
unexpected countries such as Slovakia and Hungary, and even
in the Carmargue region of southern France. In the libraries of
research institutes throughout the tropics and subtropics, it is
possible to find a plethora of research papers, booklets, proceedings of international and national meetings and national
reports on almost every aspect of rice field ecology and rice
and fish husbandry. There are many extensive bibliographies
on the subject, and even a few monographs.
Reflections from the Past
Rice fields have occupied my thoughts for as long as I can
World Aquaculture
23
remember. I was raised near a traditionally cultivated rice field that
had most of the elements of a natural ecosystem, as rice had been
cultivated there for centuries. Between the time of harvest and the
next sowing, the fallow season in the paddy fields is very interesting
for its varied fauna and flora. The diversity and numbers of organisms
each paddy supports is quite remarkable. In fact, all the seasons are
very dramatic for their changes, and at times there is an abundance
of living things and at others active life seems to be in abeyance. For
me, the rice field can be a marsh, or a pond, or a stream, all depending on a different time of year. There is always a close interaction
of terrestrial and aquatic life, and the changes seem to occur in a
harmonious continuity.
Any agricultural intervention, of course, causes some perturbation, and in rice fields the changes are quite drastic. But I am always
amazed by their intensity when the fields are flooded after sowing or
the rice is being transplanted. There is always a burst of energy, as a
wide range of aquatic animals and plants rapidly colonize the entire
paddy, arriving in the irrigation system, stimulated to develop from
dormancy, or simply having been blown in by the wind.
Which Fish to Farm
Thailand. A rice paddy and drainage ditch to provide a
nursery for cultured fish.
There are three groups of fishes commonly found in paddy fields,
each broadly defined by its origin and preferred habitat. The most
numerous are true riverine fishes, having evolved and remained in
freshwater. This group includes the large family of cyprinids - the
carps and their allies - that may number over 1,500 species. The next
are the lacustrine, or lacustrine-adapted fishes, which once had a marine connection. This is a smaller group, which includes the cichlids,
and may number about 1,000 species. Finally there are what might be
called peripheral freshwater fishes, as they comprise marine species
which recently, in the gological sense, invaded freshwater habitats.
This group includes the clupeids, or herring family, and other more
pelagic species, but are not too numerous.
Rice fields are naturally colonized by riverine fishes from local
streams. Similarly, the fields are invaded by marsh-dwelling fishes,
but those too are essentially riverine species. The large number of
tilapia species and individuals, which have become so prominent in
fish culture throughout the tropics, are cichlids. Most tilapia species
are lacustrine, having evolved in some of the oldest-known lakes of
Africa, but riverine species can also be found in both Africa and South
America. Tilapia are tropical and sub-tropical in distribution, whereas
all the carp species (Chinese, Indian, and European) used extensively
in rice-fish culture are sub-tropical and temperate.
Serious Doubts
Flow diagram of water and fish in a proposed new
system for integrating rice and production with fish
culture.
24
June 2002
The viability of rice-fish culture is a subject I have pondered for
over 50 years. At times, early in my reflections, I felt that such a
practice may well provide a substantial amount of desirable, high
quality fish at a profit to fish farmers, especially in the tropics and
sub-tropics. However, in recent years I have had serious doubts that
this is a reasonable expectation.
My pessimism runs along the following lines. A rice field is essentially a marsh that is cultivated by man, and the rice plants are
the marsh plants. The rice plants have all the priority, as they provide
the target crop. The fish that are natural to the rice field habitat are
essentially marsh-adapted fish, or fish that can live in a temporary
habitat when the water level is high and where they are fed and nur(Continued on page 64)
Bitter Harvest
(Continued from page 24)
tured. Carp, for example, have been the
mainstay of fish culture in rice fields, but
in the tropics and sub-tropics they are not
a profitable commodity. Although they are
still widely farmed, in warmer southern
China they are being replaced in fish
culture by tilapia.
The higher standard of living in China
is bringing about many social changes,
and in recent years there has been a
growing demand for higher quality food,
and that includes fish and shellfish. This
follows the trend in Europe, where freshwater carp have been eaten for centuries
but no longer have the traditional appeal
to maintain their high market demand;
and in the U.S.A., where they were introduced more than a century ago following
petitioning of the U.S. Congress by the
(mostly immigrant European) people, the
fish are now hardly to be found or eaten.
Only in Asia, in regions where food will
be in short supply for some time to come,
do carp remain a commercially viable
Request for Proposals
(RFP)—Aquacullture
Market Study
The Governor’s Office of Agricultural Policy will receive proposals for a contract to conduct a
competitive market and industry
analysis for the Commonwealth
of Kentucky for the aquaculture
industry of Kentucky.
The provisions of the entire
RFP and its required elements
can be viewed at the Finance and
Administration’s website: www.
state.ky.us/agencies/finance.
A written copy of the RFP may
be obtained by contacting Jeff Mosley, General Counsel, Governor’s
Office of Agricultural Policy, 404
Ann Street, Frankfort, KY 40601,
(502) 564-4627.
Proposals will not be considered unless received by 5:00 pm
eastern time on July 15, 2002 at
the above-referenced address.
64
June 2002
U.S.A. Harvesting the American crayfish, with the rice left available as
forage.
fish that the poor can still buy. Thus, the
abandonment of carp culture in rice fields
in Italy, Russia and Japan was, in all probability, due to the poor quality of the fish,
and not necessarily economics.
About The Future
Fish raised in rice fields will continue
to be an important source of animal protein in some remote areas of the world
where the standards of living are low, and
higher quality fish are not available. The
best possibility is that rice fields can be
part of a larger integrated system for fish
culture, particularly with tilapia. The idea
(see the schematic diagram) would be to
use the different phases of rice production
in the paddies with the different phases of
fish production. For example, during the
phase when new life is exploding, the paddies are used as nurseries for producing
juveniles, and when the rice plants are in
the growth phase the fish too are grownout, provided there is a deeper area in the
pond, or a sump, into which the fish can
retreat from time to time.
The use of rice fields as nurseries for
tilapia appears to be a feasible proposition, and one supported by Andras Szito
of the Hungarian Fish Culture Research
Institute at Szarvas, who has had a
great deal of experience with rice-fish
culture all over the world. It is also a
topic which is being widely discussed,
and even being carried out in practice
in Thailand. The principle is to integrate
the phases of fish culture closely with
all the micro-ecosystems that abound
in the rice paddies before, during and
after rice production, and move the fish
between them to take advantage of their
best benefits for survival and maximum
growth. The more long-term prospect for
rice-fish culture is, of course, a genetically modified fish, probably a species of
tilapia, which is developed specifically
for the purpose of developing viable and
commercial production.
In conclusion, the culture of fish and
other organisms for food in rice fields
has many problems that have not been
resolved, and therefore, the practice is
neither sustainable nor profitable. The
tantalizing possibilities for rice-fish culture still remain, but some new ideas and
practical innovations are required. For
example, better integration of the phases
of fish culture into rice production, as
well as agricultural irrigation schemes
and genetic engineering of a farm fish
ideally suited to the rice paddy ecosystem.
The success of crayfish, as a single crop
in rice fields, may, in fact, be showing us
the way.
Note
Herbert Fernando is Distinguished Professor, Department of Biology, University of
Waterloo, Ontario, Canada. He has worked on
freshwater ecology in six continents, specializing in rice-fields habitats, and contributed
his research to many international and national
journals. He shares his interest in rice fields
with studies on zooplankton and the ecology of
reservoir and lacustrine fishes. This is his first
contribution to World Aquaculture, but he
has written scientific articles for many popular
magazines. He can be reached by e-mail at:
[email protected]