What! Tangshan, a city that mines coal and makes steel, is actually the best in the country in terms of pufferfish farming?!

Pufferfish is a fantastic ingredient that has a place in China's long-standing food culture.

The Chinese have a long tradition of eating puffer fish, and puffer fish has been mentioned in the writings of literati of all dynasties. The most famous story comes from Su Shi, a great writer in the Northern Song Dynasty. His line "When mugwort grows all over the ground and reed shoots are short, it is the time when puffer fish are about to come out" has whetted the appetite of many people.

The Jiangnan area, located in the lower reaches of the Yangtze River, has always been the traditional production area of ​​pufferfish. Pufferfish, shad and knife fish are collectively known as the "Three Fresh Foods of the Yangtze River".

Copyright images in the gallery. Reprinting and using them may lead to copyright disputes.

However, what may surprise many people is that Tangshan, Hebei, located north of the Yangtze River, is also the "main production area" of pufferfish in China and is known as the "Hometown of Chinese Pufferfish (Redfin Pufferfish)".

At present, the puffer fish farming area in Caofeidian District, Tangshan is 14,000 mu, with an annual output of about 1,000 tons. The output of earthen pond farming accounts for more than 90% of the country, and the output of fry accounts for more than 60% of the country. The farming area and output rank first at the district level in the country, and are exported to Japan, South Korea and other places.

From the ancient food customs of the Jiangnan region to an industry in the Bohai Bay, what stories are behind the development of Tangshan’s puffer fish industry?

From "Eating puffer fish at the risk of death" to "toxic-free puffer fish"

The ancients said, "Eat puffer fish at the risk of one's life." Now we know that this is because of tetrodotoxin (TTX), one of the most toxic non-protein neurotoxins currently available. Only 0.5 mg can kill an adult. Therefore, China excluded puffer fish from legal food ingredients between 1990 and 2016.

Image source: Guo Huiqing, Liu Yuzhou, Wang Hongyu, et al. Extraction of tetrodotoxin by combined adsorption resin and ion exchange resin [J]. Journal of Guangzhou Normal University: Natural Science Edition, 1997, 2:60-63

If you want to eat pufferfish, you must first solve the toxin problem. This seems... not impossible. Pufferfish cannot synthesize tetrodotoxin by itself. It is absorbed and accumulated in the body from microorganisms (certain algae) containing TTX through the food chain. Pufferfish has a special enzyme that can convert TTX into non-toxic or low-toxic substances and store them in the liver, ovaries, skin and other parts. In this way, pufferfish can tolerate high concentrations of TTX and can also use TTX to defend against natural enemies.

By understanding the general mechanism of pufferfish's toxicity, people can greatly reduce the toxin content in pufferfish by controlling the variables in the artificial breeding environment, so that the artificially farmed pufferfish maintains a low toxicity level or even is basically non-toxic.

Tangshan, a pioneer in pufferfish farming

In the 1980s, local fishery research institutions in China began to conduct factory-scale seedling cultivation experiments on redfin pufferfish in Shandong, and achieved a breakthrough.

In 1991, the Hebei Fisheries Research Institute also made a breakthrough in this field. It cooperated with a farm in Caofeidian District and released more than 200,000 red-fin puffer fish fry for large-scale breeding.

Since then, large-scale breeding of redfin pufferfish has begun to spread in the Bohai Bay area. Especially in Caofeidian, the suitable hydrological and climatic conditions have brought natural development opportunities for the local pufferfish industry.

On the one hand, the Bohai Bay where the area is located is a natural place suitable for the survival of marine life . The semi-enclosed Bohai Bay has formed a unique ocean circulation system, with calm winds and high oxygen content in the water all year round, which provides a natural barrier for the cultivation of pufferfish.

There are also many rivers such as the Yellow River and Haihe River flowing into the ocean through Caofeidian . The abundant terrestrial runoff inputs a large amount of nutrients into the ocean, which is conducive to the survival and reproduction of a large number of plankton, and further provides rich bait for the local pufferfish farming industry.

Aerial photo of Caofeidian. Copyright image. Reprinting and using may cause copyright disputes.

On the other hand, the Bohai Bay is located in a temperate zone, and the temperature of the seawater in summer is conducive to the growth of pufferfish. Although the lower average temperature in winter is not conducive to pufferfish farming in the north, the local area helps pufferfish survive the winter by transferring them to greenhouses for farming.

In addition, Caofeidian has rich geothermal resources. After winter, the farm mixes hot water from deep wells with seawater to adjust the water temperature to a suitable temperature for pufferfish to survive, greatly reducing the energy cost of local winter pufferfish farming.

In terms of "detoxification" of pufferfish, the farms use closed factory farming and strict bait quality control to reduce the possibility of toxin accumulation in the pufferfish's body.

In Caofeidian, there is now a method of reducing pufferfish toxins by using ecological farming ideas . In this type of factory-style breeding greenhouse, the local R&D team cuts off the source of toxins in the food chain through a three-dimensional mixed breeding model of pufferfish, shrimp, and crabs. Because the toxins in the pufferfish food chain mainly come from the toxic seaweed, shellfish and other organisms that it consumes, the farm uses the food chain method to reduce the intake of pufferfish.

Caofeidian puffer fish farm. Image source: Great Wall Video

Caofeidian puffer fish farm. Image source: Liu Yadan

Li Weidong, a part-time professor and master's supervisor at the College of Fisheries of Ocean University of China, and his team members developed a seawater pond engineered recirculating aquaculture technology based on pufferfish farming in seawater ponds, achieving a major breakthrough in seawater pond farming technology . The seawater pond engineered recirculating aquaculture technology and application won the 2021 Hebei Provincial Science and Technology Achievement Award, and its achievement level ranks among the internationally advanced.

In addition, with the continued cooperation and investment of production areas and scientific research institutions, the research and development and cultivation of new varieties of Tangshan pufferfish have also made new progress.

In order to solve the problem of redfin pufferfish's germplasm degradation, local enterprises have cooperated with the Yellow Sea Fisheries Research Institute of the Chinese Academy of Fishery Sciences, biotechnology companies, aquatic companies and other institutions to breed new varieties, including the redfin pufferfish "Puffercore No. 1" and "Tianzheng No. 1". The former uses emerging molecular breeding technology to efficiently select and breed high-yield and high-disease-resistant varieties, while the latter uses traditional population breeding technology to breed high-yield varieties.

These new varieties of pufferfish allow the producing areas to further improve the quality of pufferfish while enhancing the toxin control capabilities of the breeding environment.

Based on its natural advantages and the transformation of scientific research results, Hebei quickly became the main pufferfish producing area in the north at the beginning of this century.

In 2016, my country conditionally liberalized the processing and sales of redfin pufferfish and dark-striped pufferfish, and Tangshan, which has established a complete industrial chain, quickly kept up with the pace.

More product forms

Bringing puffer fish back to the local market

With the gradual breakthroughs in technology, Tangshan's pufferfish is not only continuing to gain export advantages, but is also trying to conquer the local market.

"At first, my friends from other places didn't dare to eat it for fear of poisoning. I had to pick it up and take a bite before they dared to eat it." A puffer fish farmer in Tangshan said in an interview with the media in 2024. Now many of this farmer's old customers will buy puffer fish gift boxes from her by the truckload when the production season arrives.

Pufferfish processing. Image source: Liu Yadan

As Tangshan is close to the two major cities of Beijing and Tianjin, local pufferfish have begun to flow into the Beijing-Tianjin market in increasing quantities, increasing its popularity.

The reopened domestic market is seen as an opportunity by local puffer fish industry practitioners. How to expand the influence and trust of puffer fish in the local market is a problem that the production areas need to further solve at this stage.

In order to create a sense of safety in eating pufferfish, pufferfish companies in Tangshan have established a full traceability system from seedlings to the dining table. Customers can clearly understand all the information about pufferfish products from breeding, slaughtering, processing to final sales by scanning the QR code.

In addition, the local area has also followed the market trend and launched pre-prepared puffer fish products, such as braised puffer fish pre-prepared dishes, puffer fish dumplings, canned food, dough figurines, etc. This type of product innovation has not only simplified the difficulty of cooking puffer fish, but also helped puffer fish to be accepted by the young consumer market in a new form.

Based on the opening of such products, local companies in Tangshan have also begun to actively contact e-commerce platforms, new retailers and other channels, trying to expand the influence of their products in the local market.

Puffer fish sashimi. Copyrighted images from the gallery. Reproduction may lead to copyright disputes.

In Caofeidian, the local area has also specially built a puffer fish town , trying to combine industry with cultural tourism. In the town, tourists can visit the large-scale breeding base, or try puffer fish dishes in local restaurants. The restaurant has designed a special puffer fish menu for this purpose, including puffer fish sashimi, chopped pepper puffer fish and other dishes. These attempts have just begun.

Today, through continuous innovation in technology and products, the life and death worries about eating puffer fish have become a thing of the past, and it is waiting for a new food story in China.

Planning and production

Author: Yixiao Popular Science Creator

Review丨Liu Yadan, Researcher of Chinese Society of Fisheries

Planning丨Yang Yaping

Editor: Yang Yaping

Proofread by Xu Lailinlin