Japan bans the sale of crayfish? Do foreigners really not know how to appreciate delicious food?

On June 1 this year, the amendment to the "Alien Species Law" of neighboring Japan was officially implemented. The law designated crayfish (Procambarus clarkii) as a "specific alien species". It is illegal to sell or release crayfish in Japan. Violators may face up to 3 years in prison or a fine of 3 million yen. As soon as the news came out, it immediately sparked heated discussions on the domestic Internet. In addition to watching the fun, Chinese netizens were also confused about the news - huh? Crayfish has long been a must-have delicacy for our summer midnight snacks. How come Japanese people don't know how to enjoy such a delicious thing? Do "foreigners" really not know how to eat crayfish?

Image source: Tuchong Creative

The perception that "foreigners don't eat crayfish" is not the first time it has appeared, and the news from Japan has only further reinforced this view.

But... this is actually wrong.

In fact, not only do many foreigners like to eat crayfish, they have been in love with crayfish for much longer than we have. Compared with them, we are latecomers in eating crayfish. The Japanese ban on the sale of crayfish has another reason.

Do foreigners want to know whether they like crayfish? Why not visit the hometown of crayfish first?

Many friends have long known that the crayfish served on our table is not a native creature of China. The freshwater system surrounding the Gulf of Mexico in southern North America is its home. We want to explore the "first warrior to eat crayfish", of course, we have to look at the people living here. This is indeed the case. In the dietary traditions of local Indians, crayfish has long been a frequent visitor. When early European colonists came to explore the Louisiana region of today's United States, they had already discovered that local Indians would eat this freshwater crayfish. The French who first established a colony here quickly combined this local ingredient with the French native seasoning cajun powder to develop the "American crayfish trend" that is still popular today, especially in New Orleans, Louisiana. The way of eating with cajun powder, crayfish and potatoes and corn is far more representative of the local culture than grilled wings. The New Orleans people who love crayfish also held a food festival specifically for crayfish. For a long time thereafter, New Orleans has been the world's most important crayfish consumption position. The crayfish served on the table here every year accounts for more than 90% of the world's total crayfish production.

Compared to Louisianans who enjoy eating crayfish, Florida residents, who also have abundant crayfish resources, tried crayfish a little later. This is not surprising. Florida has a developed marine fishery. Compared with the bland crayfish, local residents prefer seafood. However, with a large number of Vietnamese immigrants gathering here after the Vietnam War, the crayfish fried in garlic butter, "Vietnamese crayfish", conquered the taste buds of local people without much effort.

The crayfish diet, which originated in the American colonies, has also set off a crayfish craze in Europe. When reports from the colonies kept mentioning this exotic delicacy, how could European gourmets resist the temptation? It was the French who first promoted the crayfish craze in Europe. However, at that time, there was no distribution of crayfish in the narrow sense - Procambarus clarkii in Europe. The European freshwater crayfish - Procambarus aristocrats, which has a similar flavor, suddenly became the favorite of European "shrimp lovers".

As the name implies, the name of the noble crayfish is probably related to the dietary habits of the European aristocracy. In the Nordic country of Sweden during this period, the royal family and the nobility were the main groups that ate crayfish. When this trend gradually spread to the people, crayfish was no longer as simple as an ordinary aquatic product. In the eyes of the Swedes, the noble crayfish is like the big elbow of the Germans and the snails of the French. It has become a part of the national food culture. And how highly is this food culture respected? Every August 7th, Swedish boys have to follow their fathers to catch noble crayfish in person to exercise the tenacity of men, and the crayfish they bring back have to go through a special cooking process - cook the noble crayfish with dill and then soak it in iced dark beer. At the happy family dinner, relatives express their blessings to the children and taste their catch together, which is quite similar to the Chinese people tasting crabs and watching the moon during the Mid-Autumn Festival.

In comparison, the Chinese are latecomers to the crayfish craze

Compared with the "crawfish-loving trend" in America and Europe, the Chinese first encountered crayfish much later. According to verifiable data, in the 1920s and 1930s, Japan introduced Procambarus clarkii from the United States as feed for bullfrog farming, and in 1929, Procambarus clarkii was also introduced to Nanjing and Chuzhou, China. Since the area around Nanjing had not yet been involved in the war at that time, it can be speculated that crayfish may have been introduced as feed animals.

In the following decades, due to its excellent adaptability and strong reproductive ability, the crayfish has been rampant in the water systems of China, becoming a troublesome invasive species. But even so, Chinese people have never had an appetite for it - this is probably because the meat of crayfish is too little. The edible part of a crayfish from head to toe accounts for only about 15% of the total weight (meat yield), while the meat yield of marine shrimp and freshwater white shrimp produced in my country is more than 65%, and even the hairy crab, which is particularly difficult to eat, has a meat yield of 40%.

This situation did not change until the 1990s. At that time, Chinese people had more money and more food. In Xuyi, Jiangsu, people first tried to use strong seasonings to enhance the taste of crayfish. The famous thirteen-spice crayfish came into being and soon became popular all over the country. In the years that followed, crayfish gradually became an excellent breeding category for poverty alleviation and wealth creation. It was widely bred in provinces such as Jiangsu, Hubei, and Anhui. Today, China has become the world's largest consumer and producer of crayfish. The crayfish production in Hubei alone accounts for more than half of the world's total production.

The Japanese ban on the sale of crayfish is really a helpless move

However, even though it has been widely eaten, crayfish (Procambarus clarkii) is still an invasive species with far-reaching impact. In China, where the price of crayfish is high, the rampant crayfish in natural water systems still pose a major threat to the native water ecology.

As an independent island country with a small land area, the situation of biological invasion in Japan is even more severe. Since the introduction of crayfish as feed for bullfrog farming in the 1920s, the scale of biological invasion caused by the escape of crayfish and bullfrogs from breeding ponds has become increasingly large. They can be seen in rivers, lakes and rice fields in Japan. The density of crayfish in some rural drainage canals is so high that more than ten kilograms can be caught in one net. The rampant crayfish not only compresses the ecological niche of native aquatic organisms, but also preys on aquatic plants in large numbers, digs holes to destroy field embankments, and even affects the harvest of rice planting. Based on this situation, in 2015, Japan proposed three principles for the management of crayfish, namely, not to discard them arbitrarily, not to release them arbitrarily, and strictly control the spread in the wild, but the results were not good. The Japanese Environment Agency has held expert seminars many times since then, believing that if the crayfish trade is not eliminated from the source, it will be difficult to prevent crayfish from constantly flowing into natural water bodies. This is the source of the "prohibition of selling or releasing crayfish" in this decree. And because Japanese people have long regarded crayfish as animal feed and the scale of their consumption is not large, this decree was passed smoothly without encountering much resistance.

In fact, the dual identities of "delicacy" and "invasive species" are also the dilemma we Chinese need to face. China has a vast territory, both land and sea, and the complex and diverse water environment has nurtured a unique ecology. However, in recent decades, many economic aquatic products, including crayfish, have enriched our lives, but have also led to an increasingly obvious biological invasion dilemma. How to better control alien species to avoid biological invasion while satisfying people's food needs is probably a question that deserves our consideration after the news of "Japan banning the sale of crayfish".

The article is produced by Science Popularization China-Starry Sky Project (Creation and Cultivation). Please indicate the source when reprinting.
Author: Wandering science writer

Reviewer: Xing Xiang, Senior Engineer, College of Oceanography, Shandong University