Hòu is a very ancient marine arthropod that existed as early as the Ordovician period 475 million years ago and is known as a "marine living fossil".
In the 1970s, the Chinese horseshoe crab was widely distributed along the southeast coast of China, and the resources were very rich, accounting for more than 95% of the world's total resources. The blood of the Chinese horseshoe crab has important medical value, and the illegal fishing phenomenon in various places is becoming more and more rampant, and the Chinese horseshoe crab has fallen into a huge existential crisis.
Chinese horseshoe crab (scientific name: Tachypleus tridentatus)
Today, it is difficult to see chinese horseshoe crabs that lay their eggs ashore north of the Pearl River estuary. On the west coast of Taiwan, the Chinese horseshoe crab has become regionally extinct, and only a small number of juvenile Chinese horseshoe crabs have survived on Kinmen Island; in Pingtan, Fujian Province, the number of Chinese horseshoe crabs has also dropped from 1,000 pairs per day in the 1950s to 4 pairs per day in 2002, and the number is still decreasing.
It is undeniable that the destruction of the ecological environment and rampant illegal fishing have pushed the survival of the Chinese horseshoe crab to a life-and-death turning point, and artificial breeding and breeding may become the last "life-saving straw" of this species.
<h1 class="pgc-h-arrow-right" > the "bloody case" of the Chinese horseshoe</h1> crab
Before being listed as a national key protected animal, Chinese horseshoe crab was also a common delicacy on the table in South China, and female Chinese horseshoe crabs with eggs were particularly popular. Due to the long-term overexploitation, the wild resources of the Chinese horseshoe crab have gradually dried up, and Guangdong, Fujian, Guangxi and other provinces have listed it as a provincial key protected animal, but the phenomenon of illegal poaching still occurs from time to time.
There are only 4 species of horseshoe crabs left in the world, and the Chinese horseshoe crab is mainly distributed along the southeast coast of China
Unlike other arthropods, the Chinese horseshoe crab has a long lifespan, grows very slowly, and takes at least 13 years to develop sexual maturity – which means that once the Chinese horseshoe crab is overfished, it will take a long time for the stock to recover. A large part of the reason why the Chinese horseshoe crab is overfished is because of the medical value of its blood.
Extraction of the blood of the horseshoe crab
In the past 40 years, scientists have found more than 50 physiologically active substances in the blood of horseshoe crabs, with great potential for development. It is worth mentioning that the deformed cells in the blood of the horseshoe crab can also have an adhesion effect with the toxin of the gram-negative bacteria, and the horseshoe reagent made according to this has extremely high sensitivity and is widely used in medicine.
At present, the world's horseshoe crab reagents are mainly extracted from the blood of Chinese horseshoe crab and American horseshoe crab, which has become the object of competition. In fact, with regulatory involvement and increased enforcement, most fishermen will release miscaped Chinese horseshoe crabs back into the sea – the real killers are the "interested" illegal smugglers. Coupled with habitat degradation and environmental pollution, the survival status of Chinese horseshoe crabs is not optimistic.
For example, in just seven years from 2002 to 2009, The Chinese horseshoe crab in Hong Kong decreased by more than 90%. A 2012 survey showed that a small number of juvenile Chinese horseshoe crabs in The Back Bay and Tung Chung Bay in the Hong Kong area survived, but the likelihood of local extinction was high.
< h1 class="pgc-h-arrow-right" > Beibu Gulf: the last "shelter" for Chinese horseshoe crabs? </h1>
The domestic research team has conducted a thorough investigation of the resource status of Chinese horseshoe crabs, and found that the Beibu Gulf area is the most ideal habitat for Chinese horseshoe crabs, and the existing number is also the largest, and it can even be said that it is the last "pure land" of Chinese horseshoe crabs on the earth.
However, even in the environment of the Beibu Gulf, the population of Chinese horseshoe crabs has been greatly reduced. In the 1990s, about 600,000 pairs of Chinese horseshoe crabs came ashore each year to lay eggs during the breeding season, and by 2010, only 300,000 pairs of Chinese horseshoe parents had been left to lay eggs, losing almost half of their breeding population.
Spawning breeding Chinese horseshoe crabs
In 2015, residents of more than 30 townships and villages in the Beibu Gulf region were interviewed by as many as 400 respondents, including both traditional fishermen and ordinary residents. According to the survey results, 95% of local respondents believe that the number of Chinese horseshoe crabs in the Beibu Gulf is significantly lower than before.
Many old fishermen pointed out that from 2011 to 2016, only a maximum of 30 Chinese horseshoe crabs could be seen every day, and at the lowest time, none of them could be seen. In the 1990s, the average local population caught at least 50 Chinese horseshoe crabs a day, and at most thousands of them could be caught at a time. These signs indicate that even in the "base camp", the resources of The Chinese horseshoe crab have still undergone a serious decline.
In 2019, the International Union for Conservation of Nature (IUCN) officially designated the living status of the Chinese horseshoe crab as "endangered", while before that, the living status of the species was "lack of data", which also shows that people's attention to the Chinese horseshoe crab has been greatly improved, and the willingness of the people to protect it has also become stronger.
The Chinese horseshoe crab is classified as an "endangered" species by the IUCN
On the other hand, as a traditional "wild game", Chinese horseshoe crab has been "strongly supported" by some consumers. In Vietnam, Thailand, Malaysia and South China, Chinese horseshoe crab was once very popular and was considered an "authentic seafood" that could improve the body's immunity.
Statistics show that in the seafood restaurants along the coast of Guangxi, the price of a 2 to 3 kilogram Chinese horseshoe crab was 300 yuan in 2018, and in 1998, the same specifications of Chinese horseshoe crab could only be sold for about 30 yuan. Driven by huge profits, many lawbreakers are desperate to take risks, and even transport wild Chinese horseshoe crabs to inland areas through logistics to make huge profits.
The Xiamen traffic police and the industry and commerce department seized more than 500 illegally smuggled Chinese horseshoe crabs and released them into the sea
In addition, in Vietnam, Thailand, Malaysia, Indonesia and other countries, illegal smuggling trade activities have also begun to sprout, which will undoubtedly bring great obstacles to the protection of Chinese horseshoe crab.
<h1 class= "pgc-h-arrow-right" > another crisis for Chinese horseshoe crabs: habitat destruction</h1>
With the rapid development of the marine economy, it is becoming more and more common (especially in Southeast Asian countries). These human activities can lead to the destruction of the natural habitat of the Chinese horseshoe crab, the reduction of spawning grounds and the significant shrinking of habitats.
Take Vietnam, for example. As a Southeast Asian country that is highly dependent on marine resources, about 20 million people in Vietnam derive their economic income from marine fishing and nearshore aquaculture. In order to develop the aquatic economy, large areas of Vietnam's intertidal zones have been converted into clam ponds and shrimp ponds, the original mangroves have been torn down in pieces, the seagrass beds have been filled in, and the quality of the ecosystem has continued to decline.
Mangroves in the Vietnam Delta (satellite image)
Mangroves and seagrass beds are important habitats for Chinese horseshoe crabs, and it is clearly not a wise approach to destroy the ecology in order to pursue a one-sided economy. Nowadays, the problem of "desertification" along vietnam's coast has become more and more prominent, there are almost no fish to catch in the coastal waters, and the "negative feedback" of ecological deterioration has begun to emerge.
On the southeast coast of China, sea sand extraction is also a very common phenomenon, which will also lead to the degradation of the spawning habitat of Chinese horseshoe crab. In short, overfishing is not the only dilemma faced by Chinese horseshoe crabs, and the deterioration of the ecological environment also needs to be paid great attention to.
In order to protect the ecological environment near the sea, China's marine protected areas have increased from 5 in 1990 to 249 in 2014, which has made the conservation of Chinese horseshoe crab a big step forward. However, at present, there are still many problems in China's protected areas, such as insufficient capital investment, weak law enforcement, and many protected areas have also been reduced to "paper parks" in name only.
<h1 class="pgc-h-arrow-right" data-track="25" > so the question is, how do we protect the Chinese horseshoe crab? </h1>
From the source of the problem, genetic engineering and other means to produce the blood of Chinese horseshoe crabs, this may be the best solution to save wild Chinese horseshoe crabs. This approach is technically feasible, but it is very difficult at the practical level. It is true that the active substances required for the reagent can be produced through genetic engineering, but the production cost is too high and the production capacity is very low, and there is currently no way to achieve industrialization.
To meet the domestic market demand, about 10 million horseshoe crab reagents need to be produced every year, and according to this demand, China consumes 100,000 pairs of Chinese horseshoe crabs every year. In the face of the pressure brought about by the "market demand", the only practical solution at present is to try the artificial breeding and stocking of Chinese horseshoe crab.
It is not nonsense to save endangered species through artificial farming, and China's baby fish (giant salamander) and Chinese sturgeon are the best examples. However, the artificial cultivation of Chinese horseshoe crab is not an easy task, the growth cycle of 8 to 10 years has increased the time cost, and the current breeding technology is not mature enough, and it is difficult for young seedlings to grow to adulthood.
The cultivation of Chinese horseshoe crab not only requires policy support and scientific research investment from government departments, but also requires bold attempts and continuous exploration by farmers and enterprises. Only with the joint efforts of many parties can the Chinese horseshoe successfully survive the extinction crisis and make greater contributions to the cause of medicine.
What do you think of the rescue plan for the Chinese horseshoe crab? Feel free to leave a message in the comments section to discuss!