Thai aquaculture: Between science and tradition

At the foot of the mountains in northern Thailand, a few dozen kilometres from Chiang Mai, the region’s major city, a colourful sign points the way to the “Fish and Coconut” farm. A dirt track leads to a huge flat area, with dozens of rectangular ponds surrounded by coconut palms. In the distance, an impressive dam on the Ping River can be seen.

The owner, wearing shorts, plastic sandals and a straw hat that shades a mischievous look, is known to all as Ajaan, an honorary title that means “Professor.” In his fifties, the son of local rice farmers, Anand Koses studied agricultural sciences at the prestigious Kasetsart University in Bangkok, before returning to the land of his ancestors.

“I saw all around me, in the Chiang Mai markets, that fish was imported from other regions, even from abroad, while we had rivers and ponds here. I thought it was absolutely essential to launch local fish production.”

The young graduate then chose tilapia farming, the most common fish on Thai farms, accounting for over 50% of the country’s freshwater aquaculture production. Today, the “Ajaan” Koses farm produces over 80 tonnes of fish a year... and 100,000 coconuts.

The fish industry is promising. According to the United Nations World Food Programme, aquatic products account for around 20% of the animal protein consumed worldwide. With the world’s population on the rise, and pressure on natural resources and land available for agriculture, aquaculture is the fastest growing food sector, offering a quick and inexpensive solution to the growing demand for fish. Already a major player on the world market, Thailand is betting on aquaculture as a major axis for economic development over the coming decades.

Nevertheless, global warming poses a major threat to the sector. “In some years, rising temperatures have caused baby fish to die, promoting the onset of disease,” says Anand Koses with a sigh. “Sometimes it can also change fish behaviour, and their feeding and reproductive cycles. We’re losing our bearings.”

Warmer surface water causes certain bacteria to multiply. And increasingly frequent flooding leads to loss of fish and sometimes the invasion of ponds by other species, not to mention damage to cages and installation walls. Here, as elsewhere in Southeast Asia, where 90% of the world’s aquaculture production is concentrated, the urgent need to adapt fish farming to climate change has been felt for the past decade.

It was against this backdrop that the Aquadapt-Nature project was born in 2012, funded by the International Development Research Centre (IDRC). The third phase began in 2023 in Thailand and Vietnam. It is part of a larger initiative, jointly funded by IDRC and the Canadian government, which has been rolling out since 2023 in a dozen Southeast Asian countries. Called AQUADAPT, this initiative aims to help small- and medium-sized farm owners adapt to climate change, while supporting the “greenest” possible development of the industry.

“We’re evaluating a range of inclusive solutions to make aquaculture more sustainable and at the service of communities,” explains Boripat Lebel, coordinator of the first project. On the day of our visit, Boripat Lebel and her mother, Phimphakan Lebel, field visit coordinator, were recording Anand Koses’ explanations as he moved energetically from one pond to the next, either on foot or on an old off-road motorcycle for the muddy areas.

This farm is one of many sites included in the project. For years, the various partner farms have been testing various strategies to become more resilient: wind- or solar-powered pond aerators to prevent hypoxia; mutual insurance or weather index insurance for risk transfer; improved communication systems... The focus is on “nature-based solutions,” a concept that involves tackling social or climatic challenges by drawing inspiration from nature to sustainably manage natural or modified ecosystems. Scientists from several universities in northern Thailand, including Chiang Mai and Ubon Ratchathani, regularly come to observe fish farmers in action. Meetings, consultations, and demonstration and planning workshops will be organized to share data and ideas.

Listening to voices from the field

“Since the beginning of the project, we’ve been giving more and more space to the perspective of the fish farmers themselves,” explains Louis Lebel, founder of the Department of Social and Environmental Research at Chiang Mai University’s Faculty of Social Sciences, who is in charge of the Aquadapt-Nature project. “Thai fish farmers have acquired knowledge of climate problems. Knowledge based on experience, not necessarily recorded, not subject to scientific protocol, but valid nonetheless. We’ve tried to listen as carefully as possible, and to be as humble as possible.”

Several scientific reports published in the first phase of the project emphasize that the climate risk-reduction strategies put in place by governments and NGOs “fail to address the needs of their main target, the aquaculture communities themselves.” “‘Top-down’ approaches and planning based solely on scientific data neglect the experience of communities [...] which, in the long run, compromises the chances of success of the plans put in place,” reads one of these articles, published in 2014.

At the farm, each pond, measuring around 20 by 40 metres, corresponds to a different size of fish: the “nursery” pond for very small fish, then the one for fry from 2 to 6 cm, some of which are marketed as fishing bait, and finally the fish that are left to grow for sale. “The optimum size is around 0.8 kg,” explains Boripat Lebel. “It’s the one that offers the best ratio between the time and money invested in breeding and the price you can get per kilo of meat. In general, customers who buy fish for their dinner want to finish the fish in one go, and not have to keep it.”

A Burmese working-class family lives on site and helps with the work: distributing food, draining the ponds and harvesting the fish in the early morning. The farm sells its tilapia to the local population. At the end of the day, when the heat starts to die down, customers flock to the market to buy fish at a lower price than at other markets in the region. A young woman has come by bike from the neighbouring village with her daughter; both leave with a big smile and two beautiful tilapia prepared on the spot.

The unclear contours of “natural”

In order to implement “nature-based solutions” for the climate transition, local know-how is a good place to start. Traditional aquaculture, which has been practised for centuries, is “socially and ecologically compatible with the local landscape, as it uses available wastes and farm by-products as feed for farmed fish,” according to New Technologies in Aquaculture, a collective work published in 2009 by renowned aquaculture specialist Peter Edwards.

For example, fish are traditionally farmed in rice paddies, a so-called “integrated” practice that combines aquaculture and agriculture.

On Anand Koses’ farm, no chemicals are used to maintain water quality, apart from salt and limestone powder to regulate pond acidity and eliminate bacteria. “The use of salts to purify water is ancestral knowledge,” recalls the owner, “even if scientists have only recently begun to take an interest in it. Lime is also applied to the bottom of the ponds.”

In Thailand, tamarind or moringa leaves are sometimes mixed with fish feed to stimulate growth and immunity. These practices have been documented by a team from the University of Technology Isan, an Aquadapt-Nature partner.

As its name suggests, the “Fish and Coconut” farm kills two birds with one stone: when a cohort of fish is sold, the pond is drained, and the water is recovered to serve as fertilizer for the 1,300 or so coconut palms and surrounding rice paddies. “Fish water is full of nutrients,” says Anand Koses. “It’s simple, inexpensive and a win-win situation.”

The fish farmer doesn’t shy away from modern technology, however, when it’s within his reach. “When we have to administer antibiotics,” he continues, “we do so using those on the authorized list, because they are eliminated from the fish’s organism before consumption.”

The farm also practises, as is standard in the industry, sex-reversal of fish. This involves administering hormone treatment to the eggs to produce only males, “because females are less profitable,” explains Anand Koses. And with good reason: they incubate their eggs in their mouths, so they eat less and put on less weight during this period. Thai scientists from outside the project have patented a technology based on the induction of electric fields for this sex change, which reduces the amount of androgens used. A “natural” solution to consider?

The concept of “nature-based solutions,” very much in vogue within UN bodies, still lacks clarity in the field. Boripat Lebel asks, “Are we talking about solutions in which every component is natural, or could it be a solution inspired by nature? For example, can a mechanical, solar-powered water oxygenator be considered a natural solution? Sometimes, reading the reports of certain international institutions, you get the impression that nature-based solutions are going to save the world. Except that no one can define exactly what it is.”

Profitable above all

The idea also runs up against financial realities. The debt ratio of rural Thai families is 90%, one of the highest in Asia. As Louis Lebel reminds us, “the economic interest of fish farmers is an essential condition for the success of any climate adaptation project.” The average salary for a fish farmer in the country is around CAD1,200 a month, almost three times that of a rice farmer, “and for less effort,” says Anand Koses, carrying a 20-kilo bag of fish feed on his shoulders. Fish farmers are therefore open to nature-based solutions, provided they remain viable and profitable. “Our farmers prefer natural solutions if they work, if they’re cheaper, which is often the case, but if a cheap chemical solution comes along, we’re not closed to it,” says Jariya Onthong of the Department of Fisheries.

Wearing a pink floral shirt and a large straw hat, the civil servant was accompanying the project team that day. Originally from a fishing family in the south of the country, she first worked in deep-sea fishing in Phuket, before taking over the management of the Aquaculture Department in the Chiang Mai region. She recalls the Thai government’s pragmatic position: “The aquaculture sector is considered a priority. Our short-term goal is to increase production volumes, but also to move production up the global value chain. The Department of Fisheries has both a technical and a marketing mission.” These ambitious goals are a double-edged sword for research teams: they benefit from a sympathetic ear from the authorities, but must not thwart the stated ambitions. “We are almost always accompanied by an official when we visit the farms,” explains Phimphakan Lebel. “They want to be kept informed, and we have to take their position into account.”

A different kind of aquaculture

Aquaculture suffers from a poor image, particularly in coastal areas, where it is practised much more intensively than inland. By discharging large quantities of organic waste, nitrogen and phosphorus, farming destroys mangroves, contaminates groundwater and leads to the eutrophication of water bodies. And they also increase reliance on sea fishing, since fish feed is made up of at least 10-30% protein... from fish. (Tilapia, on the other hand, is mainly herbivorous). Jariya Onthong admits: “The problems are mainly linked to the intensiveness of farming. For the time being, this is the only way to feed our population and generate income from exports, but smaller-scale solutions do exist, such as fish banks.”

That’s precisely the objective of the next stop: the “fish bank” in the village of Siang Pateung, a few kilometres away, another partner site in the Aquadapt-Nature project. No ponds, no fish farmers here. For the past 20 years, some 15 villagers have been managing an artificial pond of about 3 hectares, fed by the Ping River through a system of pipes. Tilapia, catfish and other snakehead fish live here in their natural state, without needing to be fed. Founding members come and fish whenever they want; for others, a fee applies, by the hour or day, whatever the number of fish caught. “We prefer to apply an hourly rate, which doesn’t depend on the luck or talent of the fishermen!” says Araya, a member of the founding team, with a smile. Fishing is only carried out from the shore, never from a boat, and a closed season of three months a year is scrupulously adhered to during the breeding season.

This type of aquaculture is considered a sideline activity, complementing a job in agriculture, for example. “I work as a cleaner in a hotel in Chiang Mai,” says Araya. “The pond is a way of supplementing my income and getting involved in community life.” A portion of the farm’s income is redistributed to members, while another portion is reinvested in the community. The use of this budget is decided jointly at group meetings, which include seven women and seven men. “The presence of women influences decisions,” says Araya. “We’re more inclined to want to reinvest in the school, in facilities shared by the villages.” By the pond, bamboo shelters, tables and chairs are set up. Families can come and grill their own fish and eat it by the water. A small hotel with bungalows has just been built on the other side of the road with part of the funds, in the hope of attracting tourists too.

Water governance

“The pond has brought the community together,” says the Siang Pateung village chief, a member of the consortium. “It’s not so easy to make joint decisions on such a vast area, which is so important in people’s lives. You have to make a lot of compromises.” On the scale of a few villages, it highlights the difficulty of water governance, a major geopolitical issue set to grow in importance over the next few years, against a backdrop of dwindling freshwater resources and the aquaculture boom. For the time being, aquaculture farms in Thailand are allowed to take water from rivers without too many constraints.

The situation could change, particularly because of growing tensions with China over the region’s main river, the Mekong. For Louis Lebel, “the increased interconnectivity between the different economies of the Mekong basin, despite major inequalities from one region to another, creates new opportunities for collaboration on water issues.” It underlines the importance of community consultation in making decisions on water allocation quotas during the dry season, avoiding illegal detour of river water and ensuring the success of aquaculture policies in Southeast Asia. “New governance mechanisms, including fish farmers for example, are needed to address these issues.”

The program described in this article and the article's production were made possible with the support of Canada’s International Development Research Centre.

This article was originally published in French in the October-November 2024 issue of the magazine Québec Science.