Shrimp cultivation: Potential and challenges

During the 1990s, to give a much-needed fillip to the economy, importance was given to shrimp cultivation in the south, especially in coastal regions. For two decades afterwards, Bangladesh earned a lot of foreign currency by cultivating shrimp, which is why the shrimp was given the nickname `white gold’.

Unfortunately, for the last couple of years, shrimp export has not been as profitable as it once was.

There are several reasons behind this. Viruses found in shrimp exported to foreign countries had a massive impact on shrimp exportation and the country's economy. In shrimp hatcheries, during fry production, some fries die. Some time ago, due to the government’s restriction on catching shrimp from natural sources, shrimp cultivation fell under huge risk. For these specific reasons, foreign export drops, and shrimp farmers start to lose interest. 85 per cent of shrimp from Bangladesh are exported to European countries. In those countries, the demand for tiger prawns and lobsters is not the same as before. There are plenty of reasons behind it.

Whatever the purpose might be, shrimp farmers, researchers, businessmen, and the government—all stakeholders—are all working on solving these issues. They are thinking about how they can increase shrimp production in Bangladesh. They are working on an alternative way, which is cheaper for shrimp production. Even so, they are thinking of improving the quality of the shrimp production sector, and research is being done on this. The people are also working on the production of white leg shrimp.

Shrimp fries are of two types. One is naturally found in salty sea water and the other in hatcheries. In a year, 650 crores of fries are produced in 50 hatcheries in the regions of Cox's Bazar, Ukhia, and Teknaf. These fish go to places like Khulna, Shatkira, Bagh-er-Haat, and other coastal regions. Hatchery production of shrimp is being used on the country’s 2 lakh and 75 thousand hectares of land covered for shrimp cultivation.

Before, the fry’s feed was imported from India, Thailand, the UK, and other countries. While bringing these products, the quality of these feeds used to drop. After eating this feed, these fries would fall sick and die. This affects shrimp exportation.

In China and Northern England, they use polychaetes as the food source for fry and mature shrimps, and they have achieved a good result in this. Taking inspiration from this note, Noakhali Science and Technology University turned to the professor of fisheries and marine science, Jahangir Sarker. He is researching polychaetes and was helped by the World Bank and the Bangladesh Agriculture Research Council. In 2021, he discovered there were polychaetes in some coastal areas. He finds out that in coastal mangrove areas about 1 foot deep, polychaetes live there. Polychaetes are like earthworms; they stay in salty water and hide in clay. Research shows, if polychaete is fed to the fry, it will lower their death rate and shrimp egg production will increase.

Not only polychaetes but also `live feed’ is an important food source for fry. Zakia Hasan is a senior scientific officer of the Bangladesh Fisheries Research Institute, As she led her team, at the beginning of 2022, a group of researchers discovered the ‘live feed’ in deep seawater. In the water environment, a tiny, green granule substance is called ‘live feed’ or phytoplankton. This is a unicellular and microscopic granule that cannot be seen with the naked eye. These life forms produce their own energy by using the carbon dioxide in the water in the presence of sunlight and, as a by-product, producing oxygen. Marine scientists are saying that in nature, there are about 1 lakh species of microalgae. On earth, more than 70 per cent of the oxygen is produced by microalgae. On a nutritional basis, microalgae are a protein source that, shortly, will be known as a "superfood."

In Cox's Bazar, in different hatcheries, these live feeds are being used. These are ideal food sources for frying. Before this, the fries food used to be imported from other countries. Hatchery owners’ organization, `The Shrimp Hatchery Association of Bangladesh, said that before, for different types of species, every 5–10 mL of live feed importation would cost them 20–25 thousand takas. Now the owners are getting it for absolutely free. As a result, fry production costs have fallen and death rates have decreased. Adding on, they said that by using live feed as the main food source for frying, shrimp production will increase. The exports of shrimp production will increase by up to 10,000 crores in 3 years. For this reason, the modern system replaces the traditional system, and the scheme of training the farmers in the ways of the modern system is a plan for the future.

People who are concerned about increasing the quantity of shrimp cultivation are working on it. Not only in enclosures but now shrimp and lobster cultivation is done even in ponds in Khulna; studies have shown positive results. In this matter, some natural and technological ideas have been used to control shrimp cultivation. To bring the situation into a favourable position, we have to maintain these terms. Such as the limit of salty water, the presence of oxygen, food management, water flow, temperature maintenance, etc. If there is less water in ponds in a whole year, lobster production can be done three times. Fry production might be less throughout the year.

Shrimp cultivation can only be done in the salty water of coastal areas and not in other places, changing this flow of thought. In 2021, a northern area called Parbotipur, a pond in that area lobster cultivation had begun. For postlarvae (PL) production at the first stage of life, salty water is needed. Salty water is brought all the way from Cox’s Bazar, Pekua and salty water is matched with fresh water and different types of water and PL production is done. Borguna, Paira River of Aamtoli, the mother of lobsters are brought, the larva is extracted from them under 28–35 days, and PL production is being done.

Around the globe, there are 450 variants of shrimp species. Bangladesh has 27 types of species; following this list are Bagdha, Chaka, Horin, and lobster; these are cultivated the most here. Whiteleg shrimp is a premium type of shrimp. Bangladesh has positive expectations for white leg shrimp, and experimental work is being done in this sector. Experts have said that if white leg shrimp cultivation starts in Bangladesh, the economic scenario would absolutely change, and the country would benefit from this.

The white leg shrimp, whose origins come from the South American region, was originally brought from Brazil. Around the world, there are different types of shrimp cultivation, and statistically, 79 per cent of these are whiteleg shrimps. Shrimp exhibitions are done in the capital city of Belgium, Brussels. In that exhibition, if 10 containers of shrimp orders are placed, the stats say about 8 containers are white leg shrimps. Our farmers are saying that in per hectare 380kg Bagdha shrimps are found. Similarly, in Khulna’s Pikegasai, there is an organization named Lona pani kendro. Their studies have shown white leg shrimps are cultivated in quantities of about 8–9 thousand kilograms.

Statistics say that in the 2013–14 fiscal year, 41 thousand metric tons of shrimp were exported. The fiscal year 2018-19 produced 30 thousand metric tons.

Our researchers have innovated the idea of making shrimp food sources widely available. If they are successfully able to meet these terms. Hence, since they have already made the food source widely available, they can surely find a safer way for soil, water, agriculture, land, the environment, and humans.

For shrimp cultivation, the soil that is being destroyed can no longer be used for agricultural reasons. Therefore, people were unemployed and had to leave their area. According to a recent study from Practical Action, we have come to know that between 1995 and 2015, in the regions where shrimp cultivation took place, agricultural land in those specific areas has decreased alarmingly.

Due to the tides, the farmers had to work efficiently; they had to break the barricades of the coastal areas for their salty water to insert into the land; other than this, they had to do plenty of work. According to the sources of the Water Development Board, Khulna Divisional Office, the local shrimp traders have built 3500 switch gates and illegally made crevices in barricades; they have made about 10,000 holes in barricades. These illegal activities have resulted into the barricades being weakened. The barricades have lost their ability to hold the water. Due to this, floods and permanent waterlogging occur. There are many adverse effects on the lives of the local people and the environment.

The writer is a columnist and researcher. She can be contacted at [email protected]