In the wake of the Vietnam War’s conclusion five decades ago, Bui Van Phong faced a pivotal decision: remain in his native village to preserve the age-old family business of crafting fish sauce or join the throng of others leaving Vietnam in search of better prospects. Phong opted to stay, nurturing the fish sauce business—known locally as nuoc mam—that has now passed down to his son, Bui Van Phu, aged 41. This cherished condiment from their village is now recognized as a significant part of Vietnam’s heritage, a fact that Phu appreciates deeply.
“It’s not solely about the quality of fish sauce; it’s about its historical significance,” Phu mentioned.
Nonetheless, there are looming threats to this heritage. Large corporations mass-produce fish sauce in factories, and climate change, coupled with overfishing, poses a significant challenge, making it increasingly difficult to catch anchovies, which are key to making the beloved sauce central to many Vietnamese and Southeast Asian dishes.
Anchovies flourish in nutrient-dense waters close to shores, forming large schools. However, climate change is progressively warming the oceans, resulting in decreased oxygen levels in the water. Researchers fear this will lead to smaller fish as larger fish, which require more oxygen, might migrate or shrink over time. Renato Salvatteci, a fisheries researcher from Christian-Albrecht University of Kiel in Germany, confirms that evidence from ancient warm periods supports these concerns.
“If the oxygen levels continue to decrease, anchovies won’t cope well,” he highlighted. “Every species has its threshold.”
Breaching this threshold could have ramifications worldwide, as the warming seas alter marine ecosystems and impact biodiversity. This could lead to an increase in smaller, less nourishing fish, escalating fishing costs, and ultimately affecting food prices. Anchovies play a critical role in the ocean’s ecology by feeding other fish like mackerel, which humans consume, and are integral in making fish meal for aquaculture.
Compounding these issues is overfishing, and geopolitical tensions in the contested South China Sea—which accounts for about 12% of the world’s fish supply—complicate efforts to manage fish stocks. Since the 1980s, destructive industrial fishing practices have been common, including dragging large nets across the ocean floor and catching everything in their path. Despite intensifying fishing efforts, fish yields have plateaued, as noted in a 2020 fishing trend analysis.
Even with ambitious goals to contain global warming to a 2.7-degree Fahrenheit (1.5-degree Celsius) rise above pre-industrial levels, coupled with halved fishing efforts, scientists anticipate that fish stocks in the South China Sea could diminish by more than a fifth. A 2021 University of British Columbia study warns of virtually complete fish depletion if temperatures rise by 7.7 degrees Fahrenheit (4.3 degrees).
While teaching information technology by day, Phu is also devoted to perfecting the fish sauce craft perfected by his ancestors. Anchovies are predominantly caught between January and March when they gather near the coast of Da Nang. Once the right species and size are secured, these anchovies are mixed with sea salt and placed in special ceramic barrels. Occasionally, additional ingredients are included to diversify flavors. The Bui family ferments their mixture for up to 18 months, stirring it weekly until it can be strained, bottled, and offered to customers.
The geographical origin of the sea salt influences the flavor, as does its quantity, with every maker guarding their recipe secrets—Bui’s recipe uses a ratio of three parts fish to one part salt. The fermentation period and potential inclusion of other fish also affect the final product’s taste.
Securing perfect anchovies has grown challenging, as the fish catches have dwindled. Fishermen lament that much of their current offerings would have been deemed too small to sell in decades past. Only through strong relationships with local fishermen can Phu bypass high market costs and secure his fish directly. Although the unmistakable scent of fermenting fish lingers around homes producing traditional fish sauce, many families contemplate exiting the business due to high anchovy costs.
This shift could impact Vietnam’s ambitions to increase its global market share, with expectations that the fish sauce market will grow from $18.5 billion in 2023 to nearly $29 billion by 2032. Vietnam, alongside Thailand, dominates fish sauce exports and hopes to leverage improvements in food safety to penetrate lucrative markets such as the U.S., Europe, and Japan, further promoting Vietnamese culture globally.
The significance of fish sauce in Vietnamese culture cannot be overstated. For Vietnamese students abroad, the flavor is reminiscent of home, and leading chefs consider it foundational to Vietnam’s culinary identity. The various flavors and types of fish sauce spark opinions across social strata—from business leaders to manual laborers—regarding which is best.
Phu emphasized that every family holds unique secrets to making fish sauce. Fifty years after his father chose to stay and sustain the family business, Phu hopes to pass these traditions to his son. However, this dream hinges on whether anchovy populations in the sea are sustainable enough for the craft to remain viable.
“For me, fish sauce transcends being just a cooking ingredient. It embodies our craft, culture, and tradition, which must be preserved, protected, and inherited,” he asserted.