REPORT #17 1998
SUSTAINABLE SHRIMP FARMING IN BELIZE


Produced by the Belize Development Trust

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 effective.

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 discharges.

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 problems.

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 government, 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.

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