Large yellow croaker is one of the four famous marine products in our country, and it is also called yellow croaker in some places. The wild large yellow croaker has vermilion lip, golden body color, neat scales, glittering in the sun, which symbolizes wealth and auspiciousness, and is highly sought after by domestic consumers.
But reality is always chilling. Since the 1970s, the number of wild large yellow croaker has been declining like a cliff. In the past 20 years, it has been very rare. The market price once climbed to 4000~5000 yuan/kg. The larger the size, the higher the unit price. Recently, a fisherman from Shipu, Xiangshan Mountain, Zhejiang Province won a lucky draw and caught a giant wild yellow croaker in the waters near Jeju Island , weighing a full 7 kilograms!
is called "giant" because wild large yellow croaker grows very slowly, with an average annual weight gain of only 300 to 400 grams. Based on this estimate, this 7-jin wild large yellow croaker is estimated to be over 10 years old, which is very rare. In the words of local fishermen, such a big wild yellow croaker "is hard to see once or twice a year"!
The crisis of large yellow croaker
In the 1960s, large yellow croaker was still a very common seafood in the East China Sea. Like small yellow croaker and hairtail, it can form large-scale fish flood , with extremely rich resources. According to data records, in 1954, the Zhoushan fishing ground could produce 300,000 quintals of fresh fish in one fishing season, of which 150,000 quintals were large yellow croaker.
There were too many large yellow croakers to eat, the market was oversupply, and the price was as low as cabbage. The fishermen in Zhoushan took advantage of the "soft underbelly" of large yellow croaker by using the knock-knock fishing method. The fishing boats returned to the port with full load, and there was a lot of waste of resources. This grand event lasted from the 1950s to the mid-1970s. This period can be called the golden age of Zhoushan fishery . Large yellow croaker and small yellow croaker set new historical fishing records.
1957,The catch of small yellow croaker hit a record high, reaching 29,000 tons; in 1967, the output of large yellow croaker also reached a historical peak, as high as 101,600 tons. With the help of the warm current of Taiwan and the coastal currents of the East China Sea, Zhoushan Fishing Ground became the most prosperous fishing ground in the country at that time. It was called a rich "fish depot on the sea" and was the "source of wealth" for hundreds of thousands of fishermen in Jiangsu, Zhejiang, Fujian and other places. ".
During the same period, the number of fishing boats in the East China Sea also increased sharply. Abundant seafood continued to stimulate fishermen to increase their investment in fishing boats, including increasing horsepower and purchasing new fishing boats. During the fish flood period from 1950 to 1952, the number of fishing boats in the Daiquyang waters (where the central fishing site of the large yellow croaker is located) reached more than 6,500, and at most more than 50,000 fishermen went to sea to catch yellow croaker .
Under the increasing fishing pressure, the central fishing ground of large yellow croaker shifted to the periphery, gradually shifting from Daiquyang to the sea area between Changlong and Samsung. However, the fishermen at that time did not realize the seriousness of the problem, and instead increased their fishing efforts. Especially in 1974, 1,200 pairs of motor sailing boats arrived at the Zhongshan fishing grounds in Zhoushan waters for the purpose of catching large yellow croaker in the winter.
Everyone knows that the next step for broodstock overwintering is to lay eggs and reproduce. If all the overwintering adult fish are caught in one net, then the result can be imagined. The next year will inevitably reduce production, and there will even be no fish to catch. Although the production of large yellow croaker in 1974 was very high, the population structure was completely destroyed. Three to four generations of large yellow croaker were pulled into fishing nets, and the entire population was hit by extinction.
In 2019, an article published in "China Marine Sociology Research" pointedly pointed out:
They caught the yellow croaker "grandma" and the yellow croaker "maternal grandfather". All of a sudden, the "house" of large yellow croaker was brought to a devastating blow to the resources of large yellow croaker. Since then, Daiquyang and the wild large yellow croaker, once enthusiastically praised by the ancients and so glorious, have fallen into disrepair.And it’s hard to get a tail!
According to Zhoushan old fishermen's recollection, there are basically not many large yellow croaker in the Daiquyang fishing ground after 1975. There are still some other sea areas, but the production is not at the same level as before. After carpet fishing one after another, the East China Sea fishery finally fell into decline, and the large yellow croaker was also in crisis.
The latest survey shows that the large yellow croaker resources in the Zhoushan fishing grounds are still in decline, which means that the large yellow croaker resources have not been restored in the past 40 years!
Zhejiang fishermen caught 7 catties of heavy yellow croaker, does it mean that the golden age is coming back?
I have to admit that 7 catties of large yellow croaker is indeed very rare, and it should be a batch of fry from around 2010. Although fished from open seas, the large yellow croaker caught by fishermen is not necessarily a purebred , but may be artificially released seed.
Large yellow croaker breeding base
There are not many breeding populations of wild large yellow croaker. On the contrary, the number of artificial release of juveniles is gradually increasing, which has a lot to do with the increase in the production capacity of seedlings in my country.
For example, on July 9 this year, National Aquatic Technology Extension Station and Zhejiang Ocean and Fishery Bureau jointly released 7 million large yellow croakers with an average body length of more than 10cm. In June 2020, the number of releases in Fujian Province reached 7.48 million, with an average body length of more than 5cm, and the longest being 8-10cm.
This kind of release activity has been persisted in our country for more than 30 years. Time goes back to 1986, when aquaculture experts from the Fujian Provincial Department of Science and Technology successfully conquered the artificial breeding technology of large yellow croaker, and in 1987 they mastered the broodstock breeding technology.By 1990, the seedling production capacity of Chinese enterprises had reached over one million, and the large-scale multiplication and release of began.
Taking Guanjingyang as an example, the number of seed released here ranges from 500,000 to 5 million. The Guanjingyang sea area of Ningde, Fujian is the last "pure land" for wild large yellow croaker. The first large yellow croaker nature reserve in China was established here. All fishermen's productive fishing is strictly prohibited in the reserve, which effectively guarantees the release effect.
Nowadays, artificial release has become the main method to restore large yellow croaker resources. If the released seed can grow up smoothly, it is estimated that the earliest batch can grow to more than 10 kilograms. However, the artificial release of the fry also has disadvantages. The characteristics of the grown-up are different from those of wild large yellow croaker. The main differences are:
- The wild large yellow croaker has neat scales , the artificially cultivated or released large yellow croaker has scattered scales .
- Wild large yellow croaker has long pectoral fins, when turned over, can exceed the front edge of the eye, and can cover the entire eye socket; artificially cultivated large yellow croaker has short pectoral fins, turned over No more than the anterior edge of the orbit, cannot cover the orbit.
Also because of this, the current release is no longer purely pursuing survival rate, but more importantly pursuing purity of blood. In order to improve the "wildness" of juveniles, some scientific research institutions have begun to use wild large yellow croaker in the Daiquyang waters as breeding parents, which can reproduce 200,000 to 500,000 at a time, up to 1 million.The benefits of this are also obvious. It avoids the degradation of traits caused by the past generations of reproduction, ensures the pure pedigree of large yellow croaker, and breeds the seed with stronger physique and can better adapt to external conditions.
In summary, the large yellow croaker caught by fishermen in open waters is not necessarily “authentic”. In addition, the number of large yellow croaker caught in the open sea is not necessarily “authentic”. Return to the golden age. But having said that, as a "delicacy" sought after by consumers, it is understandable that the price of more than 10,000 yuan per kilogram is sold. After all, large yellow croaker that grows up in the wild is also rare, and the price surge is reasonable.
Is the large yellow croaker still expected to "return to the top"?
It seems difficult to rely solely on the natural reproduction of large yellow croaker to return to the peak era of the 1950s and 1970s. Large yellow croaker feeds on small fish and shrimps, which are greatly affected by water temperature, grow slowly, and have a long reproduction cycle. These ecological characteristics are not conducive to the recovery of wild populations.
Although the egg production of large yellow croaker can reach 200 to 1 million, the hatching rate and survival rate are not ideal. In 2016, World Conservation Union conducted a population assessment of wild large yellow croaker and officially listed this species as a "critically endangered species", indicating that the large yellow croaker has not been out of danger and will still be extinct if protection is not strengthened. risks of.
wild parent "unreliable", artificial breeding has become the only hope. Although manual release has been going on for more than 30 years, as to how effective the release is and what is the survival rate, these questions have not yet been clearly answered.
It should be known that the artificially cultivated large yellow croaker is fed pellets, the environment is very stable, there is no predation by natural enemies, and the natural attributes of the juvenile fish are low. Once the young fish cultivated in the greenhouse are released into the natural sea, various factors such as water temperature, water current, bait, and natural enemies may cause a large number of seedlings to die.
Artificially bred large yellow croaker seedlings
Some domestic scholars have proposed that in the future, marking and tracking monitoring of release should be strengthened.Find out how much the artificial release has contributed to the wild population; at the same time, “training” of seedlings should be carried out, emphasizing wild domestication, stimulating the active predation of young fish, gradually getting rid of artificial dependence, and increasing the survival rate of seedlings; another point, The biological bait in the released waters must be sufficient.
The good news is that domestic companies have begun to try wild training of large yellow croaker, and the effect has exceeded expectations. The next step is to achieve scale. Of course, this project is inseparable from the continuous research and technical demonstration of experts, and R&D investment also needs follow-up follow-up.
In short, artificial release is still the safest way to save wild large yellow croaker. The quantity of release is no longer a problem. The future goal is to improve the quality of release, and at the same time, appropriately restrict fishing and improve the environmental quality of key waters. I believe that large yellow croaker can once again usher in glory!
