Rice-shrimp in the Mekong Delta 🦐🌾

A canal in Ca Mau province, Mekong Delta

The sun wakes me before my alarm, streaming in through the wide gap between the wall and the corrugated steel roof. At 7 am it’s not yet too hot, the sun still low enough to be balanced out by the breeze that sweeps the delta, rustling the banana and tamarind trees. I have not slept well. My feet are peppered with red mosquito-inflicted welts from the day before that itch persistently despite copious amounts of benadryl cream. In the stillness of the morning I ruminate on the fact that perhaps, I may not be not built to thrive in the tropics. 

This river that now surrounds me, breeding the mosquitoes that are now fat and happy on my ankle blood, is the Mekong. It begins thousands of kilometers away on the Tibetan plateau, and runs through China, Myanmar, Laos, Thailand, and Cambodia before reaching Vietnam and breaking apart into a vast, flat wetland. I am staying with a shrimp farmer’s homestay in rural Cà Mau province, at the southernmost tip of Vietnam. 

The land around me is thoroughly sculpted. Canals run in parallel lines, segmented into long rectangular pools that fit together like bricks. These are for farming rice, fish, shrimp, or some combination of all three. Narrow concrete roads flank these canals, connected by the occasional low bridge. The houses that line the roads are diverse: everything from small one-room cottages of wood and thatch to glimmering two-story houses with bright tiled walls and glass windows. Often families will simply leave their enormous front door open all day, so you can see people going about their daily tasks or lounging around in hammocks during the heat of the afternoon. My neighbors are extremely friendly: twice I was invited over for dinner, rice wine, and karaoke on the porch just because I was walking by. 

Google Maps satellite view near my homestay shows the structure of ponds, dikes, and canals

The urban Mekong 

I began my journey in the city of Cần Thơ, the unofficial capital of the Delta, located about 4 hours south of Saigon by bus. Situated on the Hau river (a distributary* of the Mekong), Cần Thơ is packed with open cafes, food carts, ornate temples, and motorbike traffic. I stayed in a small guest house in the middle of town, run by a frighteningly energetic middle-aged woman named Ms. Ha. “I’m a dragon” she said, referring to her Vietnamese birth year, “which means I work hard, I make money, I take care of people”. She seems to know everyone, and is constantly buying street food from her favorite vendors to give to neighbors, guests, or really anyone who isn’t actively eating something else. “I’m not hungry” is absolutely not an excuse, but “I just ate dinner five minutes ago” or “I have mild food poisoning” will be translated into “I’ll take it to go, thanks!”. 

A street in Can Tho

In Cần Thơ, Ms. Ha led me on a tour of the Cai Rang Floating market, a couple of kilometers up the Hau river from the city center. This is exactly what it says on the can: a vast conglomeration of boats rafted together in the center of the river, laden with produce, groceries, and even hot noodle soup to sell (my favorite is bún bò Huế, a spicy beef bone and lemongrass broth with thick rice noodles). 

*A distributary is a part of the main river that breaks off and doesn’t return back to the main stream. In a delta, the main river breaks like a fraying rope into many distributaries that fan out. 

A woman rows two lifejacketed tourists into the pre-dawn floating market

A woman sells shrimp at a daily (land) market

A land of shrimp and rice 

Rice is incredibly important in the Mekong Delta, with its rich silty soil and vast flooded plains. The region accounts for more than half of the country’s rice production, dubbing it “the rice bowl of Vietnam”. But in recent years, the industry has suffered from the combined impacts of climate change and upstream water management. 

As sea levels rise due to global climate change, ocean water moves inland and makes the waters of the Delta more salty. At the same time, a series of dams have been built upstream in China, Thailand, and Cambodia which restricts the flow of fresh water into the Delta, limiting the flushing of salt water back into the ocean. In other words, the salt is there to stay. 

A woman selling shrimp at the market

Saltwater intrusion can wreak havoc on rice crops, not to mention the fragile and astoundingly diverse wildlife of the Mekong. Farmers here have already suffered its effects, which are greatest near the coast. 

I came to the Mekong Delta because I was curious about aquaculture. But as it turns out, seafood and rice go well together economically, not just in a bowl with bean sprouts and soy sauce!

From what I’ve learned here, it seems that some form of rice paddy aquaculture is a pretty standard traditional practice: rice farmers would snatch a few fish or shrimp from their paddies to eat or sell on a small scale. But now many see this model as an important tool for climate change adaptation. In fields that are too salty to grow rice for part of the year, farmers can switch to growing salt-tolerant shrimp, providing them with a steady income. Other areas are practicing simultaneous shrimp and rice cultivation all year round. This aquatic intercropping not only provides a kind of insurance (if your rice fails, you can count on your shrimp), but also may boost the productivity of both. Disease is a major problem for aquaculture, but growing shrimp in a polyculture (along with other species) can mediate these effects. Rice plants act as a filter, rinsing the water of feces and breaking the accumulation of pathogens that accumulate in shrimp populations over time. 

While I was in Cần Thơ, I met with Mr. Tinh Huynh Quoc, the program coordinator for WWF Vietnam in his sunny office overlooking the gardens of Can Tho University. Over sliced pears and cups of tea, he walked me through the rice-shrimp farming pilot program that his group completed in 2022. WWF Vietnam staff trained 68 rural households on a specific rice-shrimp farming technique that included some other technical specifications (eg. no pesticides, raising baby shrimp in nursery ponds before moving them to the rice paddies, multiple rounds of rice planting… this is all a bit too much in the weeds for a blog post but ask me if you want to know more!). After one year, they took a look at the harvest. The new rice-shrimp farmers were able to nearly double their shrimp production (mostly due to higher shrimp survival rates), and sell their rice as organic, raising profits by 20%. Thinh says there’s still research to be done to further hone the practice, but hopefully these results are enough to get the attention of international funders. He wants to train 20,000 households in the next phase of the project. 

Cà Mau province, where I am now, also has a vast swath of mangrove forest along the south coast. People have always fished in these forests, but the government and local organizations are starting to expand the practice of shrimp farming inside mangrove areas. They hope that this will provide economic security for the area, and incentivize fishermen to protect mangrove forests instead of clearing them for shrimp ponds. The shrimp raised in mangrove forests can’t be grown at the same density, but they are much less prone to disease and are exported to high-end, environmentally conscious customers who pay top dollar for a certified “mangrove safe” product.

But this idea doesn’t appeal to everyone. Tinh Huynh Quoc told me he’s worried that giving the green light to aquaculture in the mangroves feels risky. “If someone is growing shrimp inside the forest and they get frustrated with the leaves falling down or branches in their way, they might just start cutting them down,” he explained. He thinks the best way forward would be to focus on spatial planning: design protected forest areas to offer the best ecosystem services to neighboring communities, but keep the farming separate. 

Women’s role?

Shrimp, crabs, and fish are a huge deal here: Vietnam is the world’s top producer of Giant Tiger shrimp (Penaeus monodon), and nearly 10% of the US’s imported shrimp comes from Vietnam. Despite these large numbers, shrimp farming in Vietnam is mainly done by small-scale or family operations dispersed across the Delta. Walking around Cà Mau, you can see the characteristic water-mixing turbines of a shrimp pond every couple of minutes. But on all of my walks, I never saw any women working in these farms. I heard that women are considered bad luck in shrimp ponds, but when I asked my host, Bi, he kind of laughed it off. Perhaps not everyone believes this, but gendered labor divisions seem pronounced. 

Walking through the markets of Cần Thơ, I observed that women made up the majority of sellers. Large buckets of water held live catfish, eels, frogs, crabs, and a multitude of other Mekong creatures fresh from the fishing boats. If you want one, you just have to point it out and one of the ladies will pick it up, bash it on the head with a rock, and proceed to cut out its mouth and guts with scissors. Badass or horrifying? Perhaps both.

Not for the faint of heart

There are a lot of government and NGO-led initiatives to advance the aquaculture industry here, but I’m not sure how much women are actively participating. Tinh Huynh Quoc told me that WWF prioritizes gender mainstreaming* in all of their community initiatives, but that was about all the detail he had for me on that. Hopefully I can get a better sense of this in future weeks. 

*A definition from the UN: “Gender mainstreaming involves ensuring that gender perspectives and attention to the goal of gender equality are central to all activities - policy development, research, advocacy/ dialogue, legislation, resource allocation, and planning, implementation and monitoring of programmes and projects.” … extremely broad and even a bit vague, but important!

Other climate hazards

In Cà Mau, it’s impossible to ignore how flat the land is. Even now during the dry season, the strips of land just barely peek out above the muddy waters of the canals and ponds. The entire delta is like this, just barely above sea level. Erosion is a constant threat, literally sweeping whole houses away over time. 

Given all of this, sea level rise and land subsidence* presents an existential threat to the region. A 2019 publication in Nature Communications re-calculated the elevation of Vietnam’s Mekong delta region, and discovered that much of the land is actually much lower than was previously thought. My jaw actually dropped when I read this NY Times article (give it a look!!!) profiling the study. It's one thing to read statistics, and quite another to look at the maps. Southern Vietnam could truly disappear at high tide, within a quarter century. 

*Land subsidence is when the land gradually sinks. In deltas, this can happen as sediments compact or groundwaters drain away, without being replaced by more sediment. In a natural delta, soil swept downstream by the river would be deposited like a blanket across the land with each flood. But in order to build houses and farms, people control the flow of water by building dikes and canals which prevents this. In some places in the Mekong Delta, the land is sinking 5-10 times faster than sea levels are rising!! 

Concluding thoughts

I simply cannot end on that horrifying note, so I will instead write an incomplete list of things I’ve loved about Vietnam so far:

1. Outside of the big cities, parties begin early and end by 9pm. Everyone wants to have a good time and then sleep well. I fully support this!!

2. You can get a truly exceptional meal for 1-2 dollars, anywhere.

3. Karaoke seems to be the national pastime. If you walk down the street in the evening, you’ll hear a performance on every street (mostly romantic-sounding ballads).

4. Spicy fried egg banh mi with cucumber slices and paté… !!

Tạm biệt

Grace

A formidable spread that many friends and I were invited to join