Smart technology in fish farming: a young Bangladeshi innovator's success

On a still, sultry summer night, the oxygen in a fish pond can drain away without a sound. At dawn the farmer arrives to find fish gasping at the surface, some already floating dead. Bangladesh's fish farmers know the scene well. In this land of rivers, fish farming is a pillar of both the economy and the food supply, yet the old ways of farming keep running into the same troubles: polluted water, care that comes too late, and production costs that keep climbing.

To tackle these problems, a young Bangladeshi has developed a fish-farming system built on smart technology. He says it is making the fisheries sector more modern, more environmentally friendly and more profitable. From measuring water quality to feeding the fish, from watching the pond at a distance to anticipating market demand, he has brought the whole job under the reach of technology.

To see why the innovation matters, start with the size of Bangladesh's fish sector. According to the Department of Fisheries, the country produced 4.915 million tonnes of fish in the 2022-23 fiscal year, and more than 58 per cent of it came from farmed ponds, enclosures and water bodies. Farmed fish, not the natural catch of rivers and wetlands, is now the country's main source. In the Food and Agriculture Organization's 2024 report on world fisheries and aquaculture, Bangladesh ranked second in the world for inland open-water catch and fifth for farmed fish.

The government has set a target of 6.5 million tonnes of fish a year by 2030. But space for new ponds is limited, so most of the extra fish must come from existing ponds, with more fish raised on the same area of water. That is where the trouble starts. The more densely a pond is stocked, the faster its water deteriorates, and the higher the price of a single mistake. Smart technology works exactly at that point.

Fish in this country is more than a commodity. According to the Department of Fisheries, fish provides about 60 per cent of the animal protein Bangladeshis eat, and around 12 per cent of the population depends in some way on the fisheries sector for a living. The department's Yearbook of Fisheries Statistics 2023-24 reports that production passed five million tonnes that year, and that fisheries contributed 2.53 per cent of national GDP and more than 22 per cent of agricultural GDP.

Much of that output comes from ponds of pangas catfish, tilapia, the Indian major carps rohu, catla and mrigal, and stinging catfish (shing), walking catfish and climbing perch. Commercial farms of pangas, tilapia and shing in particular keep many fish in little space, and managing water quality is the hardest part of the job. In recent years tank-based methods have also caught on, such as biofloc, in which helpful microbes turn waste in the water into food for the fish, and RAS, the recirculating aquaculture system, in which the same water is filtered, treated and reused again and again. In these systems water quality can change within minutes, so constant monitoring is close to essential.

When fish die in a small family pond, the loss is not confined to one farm. Months of spending on fingerlings, feed, medicine, electricity and labour, often with borrowed money, can be wiped out, and one bad night can leave a household in debt for years. That is where the real promise of smart technology lies: in lowering risk.

The system brings together automation, accurate data analysis and effective management to make fish farming more efficient. It has six main parts. Each can work on its own, but the greatest benefit comes from using them together.

The first part is a set of sensors placed in the pond. A sensor is a small device that measures one property of the water and turns it into an electrical signal. Here the sensors keep measuring acidity or alkalinity (known as pH), dissolved oxygen and temperature, and ammonia too. The approach is called the internet of things, which in plain terms means devices that exchange information over the internet by themselves.

• Sensor technology: constant monitoring of water quality, including pH, oxygen and temperature.
• Data collection and analysis: readings flow into a smartphone app in real time and are analysed there.
• Automatic alerts: the moment something goes wrong, a notification goes to the farmer's phone.

Why this matters becomes clear from the daily rise and fall of oxygen in a pond. By day, algae and tiny plants in the water make oxygen in sunlight. At night that stops, while the fish, the algae and any rotting feed all go on using oxygen. So oxygen is lowest just before dawn, and the danger is worst on hot, cloudy days. The farmer is asleep. With sensors in place, an alert reaches the phone before oxygen falls to a dangerous level, and the farmer can switch on an aerator and save the fish.

The numbers the sensors measure are linked to one another. The warmer the water, the less oxygen it can hold, which is why oxygen crises are more common in the heat of March to May. Fish waste and rotting feed produce ammonia, which is toxic to fish, and a higher pH and warmer water increase the share of ammonia in its harmful form. No single number tells the whole tale. The extension service of Mississippi State University in the United States advises keeping dissolved oxygen in fish ponds above 4 milligrams per litre. Guarding that level with a hand-held meter read once a day is hard; a sensor does it every moment.

Feed is the biggest cost in fish farming. Feeding by hand often gets the amount wrong: sometimes too much, sometimes too late. Surplus feed rots on the pond bottom and fouls the water. In this system the whole feeding process is automatic.

• The right ration goes in at the scheduled time, and the farmer does not need to keep walking to the pond.
• Less feed is wasted, which saves on production costs and keeps the water cleaner.

How the first two parts work together is clearest in the example of a single night. In systems of this kind the steps usually run like this:

• Sensors in the pond measure oxygen, pH and temperature every few minutes.
• The readings travel over the mobile network or the internet to a central computer.
• There they are compared with safe limits; the moment a limit is crossed, a message goes to the farmer's phone.
• The farmer switches on the aerator from the phone, or, if it has been set up in advance, the machine starts by itself.
• When oxygen returns to normal, that too shows on the phone, and the record of the whole episode is kept for later analysis.

That last step is often overlooked, but it is valuable. Months of stored readings show in which seasons and in what weather a pond is most at risk, and which feeding levels keep the water healthy. The lesson carries into the next season.

The third part is a mobile app. Through it the farmer can see how fast the fish are growing, how demand for different fish stands in the market, and how profitable the farm is. That information helps with market planning. When to harvest and sell for a good price, when to stock new fingerlings: these decisions can rest on data instead of guesswork, which paves the way to business success.

Many fish farmers have ponds far from home, and some have several spread over different villages. With a smartphone or computer, the farmer can watch and control the condition of a pond or fish tank from a distance, switching aerators or feeders on and off as needed. Even an entrepreneur living in a city can keep track of a village farm this way.

The fifth part is the drone, a small unmanned aircraft flown by remote control that takes photographs and video from above.

• Drones are used to observe the condition of the water and the behaviour of the fish.
• If damage or disease appears in a pond, it can be spotted quickly.

On a large farm with many ponds, walking every embankment takes time. From above, a change in water colour, an unusual bloom of algae or a breached embankment can be seen at a glance.

The fish themselves say a great deal. Short of oxygen, they rise to the surface and gulp; sick fish gather near the banks or swim erratically, and refuse feed. An experienced farmer standing on the bank recognises these signs, but nobody can watch every pond at once, all the time. Cameras and drone images widen that watch, and comparing them with pictures taken regularly makes anything unusual stand out quickly.

The sixth and most advanced part is artificial intelligence and machine learning, which means a computer finding patterns for itself in large amounts of past data and using them to estimate what comes next.

• Artificial intelligence is used to forecast fish production and anticipate market demand.
• It helps the farmer make the right decision at the right time.

The benefits show up in several ways. The first is productivity. According to the innovator, smart technology helps fish grow faster and healthier, and can raise a farmer's productivity by 25 to 30 per cent. The reason is not hard to see: fish that live under less stress, get the right amount of feed at the right time and suffer less disease put on weight faster.

The second is cost. Automation lowers the cost of feed and labour. By cutting water waste, automating feeding and monitoring from a distance, farmers can bring their costs down. The need to pay someone to guard the pond through the night also shrinks.

The third is the environment. Smart technology makes fish farming kinder to its surroundings. With less surplus feed and fewer chemicals going in, water pollution falls. When pond water is released, it does less harm to nearby canals and fields, and the balance of the environment is kept.

The fourth is the farmer's livelihood. When fish farming carries less risk and more profit, the farmer's finances improve. Instead of spending night after night worrying, he or she can rely on an alert from the phone.

The fifth is speed. Through a smartphone or an app, a fish farmer can get a quick answer to almost any problem. Trouble is caught early, while the damage can still be contained.

The sixth is the international market. Fish raised with advanced technology can find a smoother route into export markets, because foreign buyers want proof of how and in what conditions fish were produced. The data stored by the sensors and the app can serve as that proof.

The innovator believes smart technology will improve the quality of fish and raise demand in both local and global markets. In his view the model could serve not only Bangladesh but other developing countries as well, since their fish farmers face the same problems.

He sees room for smart pond management across the country's fish-farming projects. For that, fish farmers need training in the technology and greater awareness of it, which will bring better results. As quality improves, demand for Bangladeshi fish abroad will grow, helping to raise export earnings.

Others in the country are working on similar technology. University researchers have published designs for internet-connected water monitoring systems for Bangladeshi fish farms, proposing to measure oxygen, pH, temperature and ammonia and display the readings on a mobile app. The same studies note that many farms still rely on hand-held pH and oxygen meters, which cannot keep watch around the clock.

Smart technology is no magic wand. Sensors sitting under water gather algae and dirt, so unless they are cleaned regularly and checked against a reference from time to time, they can give false readings. When the power fails, aerators and feeders stop, so a backup supply or battery is essential. Where mobile coverage is weak, an alert may arrive late. And above all, even when the phone sounds the alarm, a person still has to act. Technology can be the farmer's eyes and ears, but it cannot replace the farmer's experience and judgement.

That is why the question of training keeps coming back. Unless the farmer knows what to do when a number changes, what to do first when oxygen falls, when to cut feed or change water as ammonia rises, even the most expensive sensor is of little use.

Even so, these limits are not an argument against the technology but conditions for using it well. The farmer who looks after the equipment, keeps a backup power supply and acts on the readings with understanding is the one who gains most. That is why the innovator puts training, alongside the machines, at the centre of his plans.

The young man's innovation has been praised internationally, and he has received several awards. It carries a message for other young innovators in the country too: the everyday problems of farming and fisheries can be a rich field for invention.

The innovator has five plans. First, to build a smart aqua centre, a hub from which farmers will receive advanced training and technology. Second, to keep developing better solutions through research and development.

Third, digital integration: linking the whole process to a cloud system. The cloud means storing and analysing data on powerful computers elsewhere, so that the farmer's own phone or computer does not need much capacity. That will make the work more efficient and lighten the farmer's load.

Fourth, low-cost supply: by offering the technology at an affordable price, he wants to spread it among small farmers. Fifth, free training for farmers in how to use it.

These last two plans may matter most. Most of Bangladesh's fish farmers own small ponds. Many cannot afford expensive equipment, and even with equipment, they will not get its full benefit without training. If the technology stays confined to large commercial farms, the overall picture of the sector will change little.

A farmer unsure about new technology has official advice to turn to. In every upazila, the Department of Fisheries office has an upazila fisheries officer who advises on pond management, fingerlings, feed and disease. The Department of Agricultural Extension's Krishi Call Centre on 16123 also takes questions on fisheries. Before buying any equipment, it is a good habit to go and see whether it is working on a farm nearby.

When choosing technology, a farmer can ask a few questions:

• For my pond's size and stocking density, which device do I need most: an oxygen sensor, an aerator or an automatic feeder?
• If it breaks, is there repair service nearby?
• What is the backup if the power fails?
• Can the app be read in Bengali, and will I understand the readings myself?

Smart technology can open new horizons in fish farming. By adopting modern methods, farmers can raise output, cut costs and increase income. Before taking up any technology, though, a farmer does well to check a few things: the cost of the equipment and its upkeep, how reliable electricity and mobile coverage are in the area, and whether after-sales service is available. Advice is also available from the local upazila fisheries officer.

An effort that began in the hands of one young man shows how great the promise of technology is in a nation of fish. When the silent danger in a pond's water reaches the farmer's phone in time, one bad night no longer becomes a whole season's loss. The question now is how quickly this marriage of smart technology and smart farming reaches the small farmer's pond.

Photo: A recirculating-aquaculture tank at a fish lab in Dhaka, Jmadhikary / Wikimedia Commons (CC BY-SA 4.0)