According to experts, the red swamp crayfish is not as nutritious and tasty as sellers advertise. The red swamp crayfish is an invasive species that disrupts local ecosystems, making its trade and farming illegal.
Red Swamp Crayfish Take Over Online Markets
In recent days, many sellers have been offering live red swamp crayfish in large quantities on online seafood markets. This type of crayfish is only as small as shrimp in Vietnam and has relatively little meat. However, traders promote them as having an incredibly appealing red color when cooked, with firm and sweet flesh. Customers can buy them to make dishes like garlic butter crayfish, tamarind sauce crayfish, or spicy stir-fried crayfish.
Currently, the common selling price ranges from 360,000 to 400,000 VND per kilogram. Compared to the same period last year, the price of red swamp crayfish has decreased by approximately 30-40%, yet it remains more expensive than the local shrimp sold in markets. The months of May to July are the peak season for red swamp crayfish in China. This year, with an ample supply flooding the markets, prices have significantly dropped compared to previous years.
Red swamp crayfish are not very nutritious, containing a minimal amount of meat.
Ms. Lê Thu Thảo, a supplier of red swamp crayfish on Facebook, shared that this type of crayfish is very hardy and popular among buyers, which makes suppliers like her very pleased. They can survive for a whole day without water. If purchased in large quantities, they can be kept in water tanks and remain healthy for a week without weakness or deaths, resulting in a very low mortality rate.
Ms. Thảo mentioned that she has received a large shipment of crayfish, and customers who place orders will get their delivery on the same day. The public selling price is just 370,000 VND per kilogram, significantly lower than the same period last year. “The red swamp crayfish available in the market are sized at 35 crayfish per kilogram, and they are very healthy,” she noted. Daily, she sources crayfish from large suppliers depending on customer demand. Some days she gets only 30-40 kg, while other days she can receive up to 100 kg.
Mr. Nguyễn Văn Long, Director of the Animal Health Department (Ministry of Agriculture and Rural Development), stated that the red swamp crayfish (scientific name: Procambarus clarki) is listed in Appendix II of the species of foreign organisms at risk of invasive harm, issued in a circular by the Minister of Natural Resources and Environment in 2018.
Live red swamp crayfish are also not listed in Appendix VIII of the list of aquatic species allowed for trade in Vietnam, as stipulated in Decree No. 26 of 2019 by the Government detailing certain provisions and measures for implementing the Fisheries Law.
According to fisheries experts, red swamp crayfish can become a disaster for the agricultural sector. Their behavior involves burrowing in the substrate, preferring to dig burrows, being nocturnal, and can create burrows as deep as 100-200 cm. They can live both underwater and on land and can withstand temperatures ranging from 0 to 37 degrees Celsius. Their primary diet consists of organic detritus, grains, soybean meal, vegetables, young grass, aquatic plants, algae, insects, small benthic organisms, and decomposed animal matter.
Red Swamp Crayfish are Mostly Shell, Meat is Not as Tasty as Advertised
Dr. Nguyễn Quang Huy from the Institute of Aquaculture Research I stated that Vietnam imported red swamp crayfish from China and conducted experimental farming in Phú Thọ, Ninh Bình, and Hà Nam provinces in 2006. The results showed that this species hides among the roots of rivers and lakes, even crawling onto land to breathe oxygen, often digging burrows 1-2 meters deep, which poses a risk to agricultural irrigation systems. They also serve as hosts for many diseases that can spread to the environment and compete for food, threatening native shrimp and fish species.
Red swamp crayfish are hosts that transmit and spread many diseases to their surrounding environment.
Dr. Nguyễn Quang Huy indicated that introducing this species for farming in Vietnam might provide some short-term benefits, but the long-term agricultural damage they can cause is tremendous. They spread quickly, are more difficult to eradicate than golden apple snails. If farming red swamp crayfish is not banned, it poses a high risk of significant damage to biodiversity, ecological environments, aquaculture sectors, and rice production, leaving long-lasting negative consequences.
Experts emphasize that red swamp crayfish are hosts that transmit and spread various diseases to their residing environments. Many countries prohibit farming red swamp crayfish, while some allow it in designated areas but with strict controls. In countries where farming is permitted, the natural conditions are often unfavorable, leading to the necessity of allowing this species due to economic benefits, but with accompanying strict control measures.
Regarding claims that red swamp crayfish have meat tastier than tiger shrimp, Dr. Nguyễn Quang Huy noted that red swamp crayfish contain only 30% meat and 70% shell, and that the meat and nutritional content is not higher or tastier than the tiger shrimp and whiteleg shrimp currently available in Vietnam. Red swamp crayfish do not have high economic value.
They yield very little meat; for a kilogram priced at around 400,000 VND, there are only about 300 grams of meat, with the rest being shell. Compared to local shrimp species like tiger shrimp, whiteleg shrimp, and giant river prawn, they cannot match in taste. Many people try red swamp crayfish out of curiosity but will likely lose interest over time. “We have many better shrimp species to choose from; why allow the farming of red swamp crayfish, which poses so many risks?” an expert questioned.
According to Dr. Nguyễn Quang Huy, if farming these species is not banned, the biodiversity, ecological environments, aquaculture sectors, and rice production will face a high risk of significant damage, with long-lasting repercussions.
No one should buy, sell, or consume them regardless of how delicious or cheap they may seem, as it is crucial to protect the biodiversity of the local ecosystem, ensure the sustainability of agricultural ecosystems, and safeguard food security for a country that widely cultivates rice and still has fragmented agricultural practices like ours.
At one point, the Ministry of Agriculture and Rural Development had to issue an urgent letter demanding provinces, cities, and relevant authorities take action to prevent and eradicate red swamp crayfish. If discovered, they must be destroyed immediately, and strict penalties should be imposed on any trading activities to prevent the spread of this invasive species into the environment.
