For hours they fillet, salt and dry fish. What stink, ask the dried fish makers of Phuoc Hai Town in Ba Ria-Vung Tau. 

In Phuoc Hai Town of central Vietnam's Ba Ria-Vung Tau Province, 40 households earn their daily living by drying fish. Nguyen Bich Van runs the biggest such production facility on a 1,800 square meter area. Everyday, it dries over 3 tons of fish like croaker, ray and spotted eagle ray, and collects over 1.5 tons of dried fish.

Van buys the fish from merchants at a dock located one kilometer away from her workshop. The majority of the fish are croakers, sold at VND20,000-50,000 ($0.86-2.2) per kilogram, depending on the quality.

First, the fish are dropped into a scale remover. "In the past, we had to remove the scales by hand which was hard work and took a lot of time. Now, the scale remover takes just a few minutes to strip hundreds of kilograms of fish," said Le Tam, a 45-year-old worker.

Next, the fish are dropped and scattered onto the floor next to 20 workers, all of them local women. They proceed to cut off the heads and tails of the fish and slice them in half.

Before the drying process begins, the fish are first thoroughly cleansed with seawater to preserve their freshness. Once drained, they are seasoned a little or a lot depending on the market.

"In order to deliver a delicious, chewy but not musty product, the fish must absolutely not touch fresh water during the manufacturing process," a worker said.

Under the blazing noon sun, workers use a trolley to bring out baskets of fish to the drying yard that is a few meters away from the other stations.

The drying racks are wooden frames with tight-knit nets that measure one meter in width and 1.7 meters in length.

In sunny weather, the drying process takes two to four days. In the rainy season, however, it takes longer and sometimes the fish are put into a special oven instead. Throughout this process, the stink is pervasive, but the workers said they barely notice it.

Every few hours, Nguyen Thi Nam, 53 years old, comes out and flips the rays so that they dry evenly. "Rays take the longest to dry," she said.

The salary of a worker at the workshop depends on their position and efficiency. For example, they are paid VND2,000 ($0.1) for every kilogram of beheaded or dried fish. Nam earns VND200,000 ($8.6) per day on average. Younger women and men typically earn VND300,000-400,000 ($13-17.2) per day.

Batches of dried croakers are stacked into a pile on the mat before being packaged.

Rays sell for VND100,000 ($4.3) per kilo, while croakers can sell for up to VND150,000 ($6.4).

Every year, Phuoc Hai Town provides thousands of tons of dried fish to markets like southern Vietnam's Ba Ria – Vung Tau, Ho Chi Minh City, Binh Duong and Tay Ninh. "Last year, our net profit was around VND200 million ($8,600)," Van said.