REPORT #17 1998
SUSTAINABLE SHRIMP FARMING IN BELIZE
Produced by the Belize
We first brought to attention of the government that there was
a shrimp crop in Belize back in the 1960's with some paper
reports to the Ministry of National Resources from the old,
Fisheries Research Station on Caye Caulker. We did some trawling
experiments with a net donated from the Oregon 1, Research Ship,
from the USA. This Caye Caulker based Fisheries Research Station
was replaced by the formation of a Government Fisheries
Department a few years later. Adam Smith an American processor
came in, after the Nicaraguan troubles and did some experimental
trawling and then brought in trawlers on a seasonal basis to work
the shrimp season in the lower half of the country. The fishing
cooperatives eventually took over this operation.
It took another decade and a half to introduce the idea of
shrimp farming. Various reports and correspondence were carried
on worldwide and passed on to Belmopan, but an investor, or group
of investors did not exist. At this time, the shrimp farming in
India, Malaya and in Ecuador and Panama were now operational.
Belize having ideal territory for shrimp farming was next.
There is a growing world wide shortage of all sea foods. The
higher paid limited crops like lobster, conchs and shrimp will
always have a market. It is like having money in the bank, or a
hidden reserve of gold coins.
A lot of knowledge, problems and ecological environmental
effects are now known, that were not known a decade or two ago.
Shrimp farming in Asia has run into considerable trouble in
recent years. Destruction of mangrove coastal zones to build
ponds, was a political decision found to be in error. We now
know that shallow lagoons, ponds, creeks and mangrove belts of up
to a half mile wide are needed to cleanse the pollution coming
off the mainland. The chemical reactions and combinations of
atoms and molecules that by natural process convert toxic
pollutants into harmless natural substances are almost impossible
to duplicate by man made substitutes. The alternatives are
hundreds of millions dollar investments to create substitute man
made ponds and algae beds for the conversion of toxins and
pollution before running off into the sea. The natural
filtration conversion system of mangrove belts is superior in
every way. Not to mention that it is FREE and very cost
Unlike many ocean shore countries, Belize has an inner sea,
inshore fisheries and offshore great barrier reef and islands.
These would be severely damaged as the population levels rose to
half million and the one million people mark, without these
natural coastal filtration systems. Pollution comes not only
from shrimp farms, but from chemicals, fertilizers, feces, waste
treatment plants, garbage dumps and many other causes.
In order to protect the inshore fisheries and offshore reefs
the cost to future governments some thirty to fifty years away
would be awesome( in the hundreds of millions of dollars), to try
and duplicate the already existing natural filtration system of
mangrove belts along the coast of Belize.
At the moment in Belize, there are laws protecting the
environment and mangrove belts, but no enforcement, or very
little and the little that is there, is also politically
motivated. If you are politically connected you can chop down
and dredge as much mangroves as you wish. This is a problem that
must be faced as the population grows.
Shrimp farms that are huge, are usually well managed. In
countries where small farmers have a few ponds, they often cannot
afford the huge costs of a well managed Shrimp Farm Operation.
The solution has been found, to band these small shrimp farmers
into co-operatives, so by joint effort and cost sharing, they can
meet the standards set by government for water clarity and
When the population is small as in Belize today, there is a
tendency to look at coastal wetlands as expendable lands, for the
greater immediate need of commercial exploitation and a growing
tax base. The results are now in, from Thailand and other parts
of Asia. To ignore the benefits of coastal filtration systems is
a disaster and more expensive in the long run. The longer run is
not so far away either, just about thirty years in Belize.
The natural shrimp cycle is for shrimp that have mated in the
ocean, or inner sea of Belize to spawn their eggs that will turn
into larvae. These larvae feed on plankton. Belize is not very
rich in plankton. About 12 days later the larvae migrate into
the coastal zone, into the more nutrient rich mangrove, creeks
and lagoons of the coastline. Here they grow into juvenile
shrimp and are flushed back out into the ocean by the changing
water salinity during the rainy seasons. The whole coast of
Belize from the Rio Hondo, New River and all the way down to the
Sarstoon River in the south produce shrimp. I have caught shrimp
with a plain old plastic pig tail bucket on the night tide,
anchored off the village of Chunox in the river. Just by dipping
it over the side of my boat, as they float out to Chetumal Bay.
Shrimp farming, attempts to duplicate this cycle of life for
shrimp. Shrimp farming uses manipulated lights, temperature,
salinity, hormone cycles and nutrient supplies to speed up the
process of growing shrimp.
In hatcheries, the eggs are transferred to rearing tanks where
they can mature as larvae in reasonable safety. Tiny shrimp feed
on microscopic algae. When they get bigger they receive
commercial feed. Young shrimp are kept for about three weeks and
then transferred to open ponds.
There are two ways to do this type of operation. You can
catch the larvae and young shrimp by subsistence fishermen and
transfer them to ponds, or hatchery rear the whole life cycle.
The hatchery method is more consistent in producing a steady
product and even profits. In countries like Ecuador where the
catching of larvae has been the method used, the offshore shrimp
trawlers have seen their catches decline alarmingly. It is not
clear from a scientific viewpoint, whether the catching of shrimp
larvae by fine mesh nets for sale to shrimp farms has depleted
the offshore shrimp trawling harvest, but there is obviously a
trade off and some price to pay. An added problem is that 100
pounds of additional sea creatures are also killed and discarded
for every pound of shrimp larvae harvested in this manner.
There are a variety of ways to raise shrimp in ponds. You can
do casual harvesting, or intensive production and a varying
degree of many shades in between. Some ponds are fed by natural
tidal flow and others use pumps and gravity feed lines, or
canals, to make a water flow. Large natural flow type ponds
produce about five shrimp per each square meter of pond. Feeding
is done by lacing the ponds with fertilizer and manure to promote
the growth of algae on which the shrimp will feed. The more
intensive ponds use fish feed pellets made from plant and fish
meals with binders to stabilize the feed while under water.
Production can be around 892 pounds per acre or 2000 pounds
per hectare. The time required is 100 to 120 days, or 4 months.
More intensive production systems use aerated water and oxygen
systems and can produce up to 3,200 pounds in the same cubic
volume of water. It takes about two pound of feed to produce one
pound of shrimp. Shrimp are not that efficient in converting
food to meat. Even in the best controlled systems at least 30%
of the feed is wasted. In the less intensive systems 60% of the
food is wasted. This waste is in the form of uneaten feed,
feces, ammonia, phosphorus and carbon dioxide. Excess waste
floats to the bottom of the ponds stimulating phytoplankton and
consuming large amounts of needed oxygen. In traditional less
intensive systems, these wastes are flushed out to sea, or into a
nearby river. This can cause fish kills due to oxygen
deprivation. The old fashioned way was to flush ponds once a
day. The main chemicals put in ponds are fertilizer to stimulate
the growth of plankton on which the shrimp can feed, agricultural
limestone and burnt lime for adjusting the acidity of the water
and underlying soil. In Asia, the shrimp farmers also use porous
minerals such as, zeolites to remove ammonia and calcium
hypochlorite to kill pathogens and pests.
The problem with all these additives, is that they can
overwhelm the ability of coastal zones to assimilate and convert
these waste products. Too much effluent being discharged
directly into the coastal zone will see the local ecosystems
overwhelmed. This has backfired in the past and the incoming
water supply has then been contaminated for the shrimp ponds.
Viral diseases are now on the rampage in countries where
concentrated shrimp aquaculture and many farms have degraded the
local coastal zone water supplies. Shrimp farming in recent
years in both Taiwan and mainland China has collapsed from these
Pathogens can travel from continent to continent and country
to country in shipments of infected hatchery produced shrimp.
Diseases of shrimp can also be spread through uncooked selling
methods and frozen shrimp. There is a new danger now in that
some farmers are using antibiotics and this is causing new
bacteria to develop against which there is no resistance. This
can upset local ecologies in unforseen ways.
Some of the new rules for ponds are plastic liners, or clay
formations to halt seepage. To halt the discharge of effluents
into freshwater bodies like rivers and creeks. Shrimp ponds
being constructed in tidal wetlands, estuaries lagoons and such
are now forbidden in many places. Nor are they permitted in
mangrove swamps and locations.
The use of natural processes and resources of a country
without forethought for the future and self sustaining ability of
the operations is a new thing for governments to think about. In
Belize we have sand excavations from beaches, sand and gravel
mining operations by politician controlled commercial operations
of Natural Parks along the Sibun River. Shrimp aquaculturists
are no less guilty of using public resources without recompense to
or thought for the future and self sustainability and many governments
are blind to the future implications. Or just weak and cannot
enforce the regulations they have on the books, due to poor
government systems and corrupt constructed Constitutions.
Some changes can be introduced. Increasing the survival rate
of young shrimp from about 30% to 75% would be a start. More
effective rationing ways of feeding shrimp another. The damage
from reduced effluents would then become more manageable. Income boosts
from such efficiencies should compensate shrimp farmers for their
efforts. There are no final answers, compromise is still
necessary. The learning experience goes on.