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Yangtze River Swordfish
Release time: 2006/2/17 9:03:04
Yangtze River saury, the scientific name is Longjaw bream, also known as sword bream. Its body is long with flat sides, and its belly is silvery and greasy. It is named after its shape like a sharp knife. Distributed in the Yangtze River and coastal brackish water areas, they enter fresh water from the river mouth during the reproductive season and migrate along the main stream to the birthplace in the middle reaches of the Yangtze River, as far as Dongting Lake. Some spawn in the main stream of the river, and some enter tributaries and rivers and lakes. Mooring to spawn. After spawning, the broodstock disperse in fresh water to feed, and then slowly return to the estuary and offshore waters to continue fattening. The juveniles of long-jawed bream also migrate along the river to the estuary area to be fattened. In winter, long-jawed bream do not migrate long distances, but gather in deep offshore areas to overwinter. It is a typical migratory fish species.
Question about the sky-high price of Yangtze saury: Behind the vegetable price of 10,000 yuan is the painful ecological cost
Long and flat on the sides, with a silvery and fatty belly, this fish is named after its shape like a sharp knife .
The Yangtze River swordfish, whose scientific name is Longjaw bream, is also called sword bream. Relatively speaking, people are more familiar with another fish of the same genus - anchovies, which is the common name of anchovies. Like anchovies, they are two closely related fish that usually inhabit shallow seas near river mouths in eastern China. Every spring and summer It swims upstream to lay eggs and is a typical migratory fish species.
Residents in many cities along the Yangtze River call Yangtze saury Jiang Dao. They know that compared with anchovies that are fried and packed in tin cans and sold for six or seven yuan a box, Jiang Dao There is a world of difference in their worth - in a hotel in Jiangyin, three river knives were worth a pound, steamed and put on a plate, and the price was 10,000 yuan. This is the latest sky-high price this year.
Some older Jiangsu people also know that this huge price difference was formed in the previous 20 years. Once upon a time, people in cities along the river could taste fresh food a few times during the Qingming Festival, just like admiring chrysanthemums and eating hairy crabs under the full moon in the Mid-Autumn Festival.
"Look at the net and the silver knife will come out" is a saying of Su Shi in the Song Dynasty, and Li Yu in the Qing Dynasty called it "a wonderful spring delicacy". Historical data shows that the fishing output of swordfish once accounted for 35% to 50% of the natural catch of fish in the Yangtze River, of which the proportion in the Jiangsu section was as high as 70%. Nowadays, the Jiangnan custom of ordinary people eating Jiangdao in spring has become a luxury . In 2005, a Shanghai media wrote in an article: "Have you ever eaten Yangtze saury? If you ask this question to today's young people, I'm afraid you have to change the question to: Have you ever seen saury?" On May 1, along the Yangtze River The swordfish fishing licenses in the hands of fishermen have expired, and this year's swordfish season has officially ended.
As of now, there are no exact statistics on the overall catch of saury in the Yangtze River in 2005, but market conditions have proven that it is a foregone conclusion that this number has dropped from last year. A data from the Freshwater Fisheries Research Center of the Chinese Academy of Fishery Sciences shows that the output of river knives along the Yangtze River was 3,750 tons in 1973, about 370 tons in 1983, and less than 100 tons in 2002.
“This is not a straight line decline, but a geometric decline, which proves that our utilization of swordfish resources has reached its limit.” said Shi Weigang, director of the Resource Research Office of the Freshwater Fisheries Research Center.
Within two weeks, reporters visited many cities in the lower reaches of the Yangtze River and found that behind the exponential decline in catches, the expensive Yangtze saury was a loss rather than a gain for fishermen and operators. ; In the eyes of scholars who are trying to save the swordfish population, it is the entire Yangtze River ecology that has really paid a heavy price.
Fisherman Chen Chusheng’s saury season
Chen Chusheng also admitted that throughout the saury season, he and his younger brother’s family only caught about 300 kilograms of saury in one day, which was only the same amount. The catch in one net in the 1980s.
At 7:54 a.m. on April 26, a 30-centimeter-long river knife was pulled out of the river. The fish's body shone in the sun quickly slapped the water, and then the fish stuck in the net was suspended in the air. When it got up, it desperately turned its head towards the river, its body turned left and right, bending into stiff semicircles again and again.
This is the first Yangtze River saury caught by Changshu fisherman Chen Chusheng that day. Two hours ago, he and his brother Chen Chugen each drove a diesel-powered fishing boat and set out from Changshu Hupu Fishing Port. Drive eastward into the Yangtze River section near Sutong Bridge. This is 62-year-old Chen Chusheng’s favorite Jiangdao fishery.
At 7:10, Chen Chusheng’s wife Lu Fengying and his youngest son Chen Liang cast a gill net into the river between the two boats.
Five or six minutes later, the large net, which was more than 500 meters long, was dragged forward by the two boats in an arc along the river. The river here is shallow and fast, and has always been a river saury channel. A gill net with a grid of 3 cm square reaches the bottom of the river, which can intercept fish schools.
This morning, after repeatedly casting the net and dragging it twice, the Chen Chusheng brothers got their biggest catch in the saury season: a large and small Jiang Dao ***159, about 30 kilograms.
But Chen Chusheng himself was not as excited as the reporter who witnessed this process. The harvest came too late. It was already the season when Jiang Dao was out of the market, and the purchase price offered by the fishmongers was not as good as during the peak period. One tenth.
More than a month ago, fishermen on the Yangtze River would see fishmongers speeding by in speedboats. The latter searched for every fishing boat that caught river knives and offered 700 to 1,000 yuan per catty. The high price, and in the market at that time, Jiangdao once had a sky-high price of 2,000 yuan per catty.
But at that time, Chen Chusheng could only wave at the dealers.
On March 15, this old man who had been fishing for saury all his life cast the first net of the 2005 saury season. The unprecedented high prices in the market made him feel like he was facing a gamble with the highest bets. "When I turned the throttle of the boat, my hands were shaking a little," Chen Chusheng said.
That day, when the gillnet more than 500 meters long was slowly pulled out from the river, Chen Chusheng saw the first empty net in his fishing career. On that day, he* **I cast 4 nets, all of them were empty, and the saury was nowhere to be found. After eight days, he still found nothing. On the ninth day, the first river knife of 2005 appeared on his razor net, but the harvest in that whole day was only 2 pounds and 8 taels.
“This has never happened in any year. My feeling is that this year’s saury is at least half less than last year.” On April 26, Chen Chusheng expressed his unfavorable start to this year’s saury season. Still brooding, he lowered his head expressionlessly and rowed the board of the boat unconsciously with his right index finger. His son Chen Liang took over the conversation at this time, "My dad has been fishing for river swords for decades, and he has never encountered an empty net before this year. Can you imagine his mood? A farmer has been farming for a year, but in the end there is no harvest. , how would you feel?” In fact, when the reporter informed a staff member of the Changshu Fishery Administration Station about Chen Chusheng’s harvest on April 26, the other person simply couldn’t believe it, “Will there be so many?” /p>
The most fish this year has been in the past few days, but a boat catching 10 kilograms a day is considered a good harvest. "This fishery official has reasons for his surprise. This spring, many cities in Shanghai, Jiangsu and Anhui have caught fish. The media raised alarms about the "missing" saury. Shanghai's "Wen Wei Po" reported on April 1 that Nantong fisherman Li Jingui only caught 5 saury after dozens of days of fishing in early February.
Chen Chusheng also admitted that the harvest on April 26 was his rare luck this year. During the entire saury season, he and his brother's family only caught about 300 kilograms of saury in one day, which was only equivalent to the catch in one net in the 1980s.
This old fisherman has a clear table of river knife production in his mind: "Before 1973, we also used two boats to catch river knife, but the boats were rowing sailboats. The nets were only three One-third of the length, and the quality is not good. Once you catch a fish, you need to mend the net once. But around the Qingming Festival, you can catch at least 200 kilograms of Jiangdao, and at most, you can catch more than 600 kilograms.
“In 1973, the number of river knives was the largest. A master in our village caught 10,000 jin of river knives in one month before and after the Qingming Festival. I caught about 6,000 jin that year. The largest jiangdao I ever caught weighed 6 ounces. At that time, jiangdao were evenly sized, and four fish were enough to weigh one pound. “After 1973, Jiang Dao became smaller and thinner year by year. The number dropped the fastest after 1995, but at that time there were only 40 or 50 kilograms per net, and in 1997 only 20 or 30 kilograms per net could be netted. "Around the Qingming Festival in 2002, when the net was cast, there were only one or two." That year, the price of Jiang Dao sharply increased, and the purchase price on fishing boats increased to 500 yuan per catty. In 2003 and 2004, the number of river knives dropped not significantly, but the purchase price of fishing boats rose to 650 yuan per catty around the Qingming Festival. ”
The source of the sky-high price of Jiang Dao
The Yupo Farmer’s Market in Xingang Town, Jingjiang City, Jiangsu Province was an important source of the sky-high price of Jiang Dao two months ago. It has appeared many times in the market There was even a fight over the "fish grabbing" incident.
On the morning of April 29, at the Yupo Farmers Market in Xingang Town, Jingjiang City, Jiangsu Province, which is dozens of kilometers away from Chen Chusheng’s fishing boat, every aquatic product store still had saury for sale. At this time, more than 2 taels of saury were sold. The price is more than 100 yuan per catty.
This seemingly peaceful largest farmer’s market in Jingjiang City was an important source of the sky-high price of Jiang Dao in 2005 two months ago.
“At the end of February and early March, the price of Jiangdao here was 1,800 or 1,700 yuan per catty. This good market lasted for a week, which was about 300 yuan higher than last year.” A person said The stall owner surnamed Liu played with the ice on the saury fish and recalled with some excitement.
During that time, many luxury cars parked at the entrance of the market every day. Car owners from places such as Shanghai and Nanjing request to buy authentic Yangtze saury, but many of them will be "persuaded" because the saury is seriously out of stock and it is difficult to buy it no matter how high the price is. It depends on "relationship".
That was also the time when fisherman Chen Chusheng was worried about his empty net. Obviously, the price of Jiang Dao was directly related to the fishing boats on the river.
The reason why wealthy customers flock to the Yupo Farmers Market to buy "authentic" saury is also related to the migratory habits of the Yangtze saury. Jingjiang has been known as the "Hometown of Swordfish" since ancient times. It is said that the farthest point where the sea tide pours into the Yangtze River Estuary is just at Jingjiang New Port, where river knives have gathered in groups since ancient times. Moreover, when they migrate here, the salt content in the fish body gradually dilutes appropriately, and the gonads begin to accelerate development, so The river knife produced in this section of the river has the most delicious taste.
Local market sources revealed that the actual production of saury in Xingang, Jingjiang City this year was very small. Most of the saury was brought from Shanghai and other river sections in Jiangsu, and the name "Jingjiang saury" was used to attract high prices. What's more, sea knives caught in Shanghai and lake knives caught in Chaohu, Anhui and other places are "gilded" in local rivers and passed off as river knives.
As the name suggests, Hai Dao refers to the saury fish caught in offshore waters that has not yet migrated, while Hu Dao is a similar species of Jiang Dao that has lived in fresh water for a long time. Real eaters know that although Hai Dao and Hu Dao are not the same as Jiang Dao, The appearance is similar, the taste is incomparable, and the value is incomparable.
Another stall owner told reporters that when Jiangdao was first launched this year, there were many "fish grabbing" incidents in the market, and some people even fought. There were scenes of Jiang Dao being auctioned in some aquatic product stores. Someone confirmed that the most expensive Jiangdao weighs more than 2,000 yuan per pound.
This spring, the price of Jiang Dao has soared unprecedentedly, becoming a common phenomenon along the Yangtze River. Several local media have reported on this: On March 15, the retail price of Jiang Dao in Nanjing was contrary to the norm of gradually declining after its launch in previous years. The price of a bar weighing 150 grams (3 taels) dropped from 2,400 yuan/kg at the beginning of the market. The price soared to 3,000 yuan/kg, a new high in the past four to five years.
In March, the price of one kilogram of Jiang Dao was as high as 4,000 yuan in the Suzhou market.
In March, Jiang Dao in the Shanghai market exceeded 4,000 yuan per kilogram.
On April 12, the "Yangtze River saury" on the market in Tongling, Anhui has been "fully launched" and is priced at a sky-high price of 3,600 yuan per kilogram. Although this Jiangdao is suspected by experts to be an old product that was frozen the next year.
"Before the Qingming Festival, the fish bones are as soft as cotton, and after the Qingming Festival, the fish bones are as hard as iron." The appetite of diners is also an important determinant of the market price of Jiang Dao.
Since ancient times, saury, anchovy, and puffer fish have been collectively known as the "Three Delicacies of the Yangtze River". Because saury was the first to be marketed, it ranks first among the three delicacies. However, this fish has many fine spines in its body, so the fish bones The changes in softness and hardness before and after Qingming greatly affect its taste.
A Nanjing diner who loves eating Jiang Dao described: "The Jiang Dao before Qingming Festival is tender and smooth, extremely delicious, and the fish bones melt in your mouth. It feels like you just want to close your eyes." Tasting it carefully, you will be intoxicated. "Li Yu, a gourmet in the Qing Dynasty, also wrote: "When I get tired of eating crucian carp and sturgeon, the more I chew, the sweeter it becomes, until I feel full and can't eat it anymore." Knives have become one of the most fashionable gifts in the Yangtze River Delta cities, but the one that best reflects their value is a plate of steamed saury in restaurants.
Jiangyin City is across the river from Jingjiang City, and its economic strength ranks among the top 100 counties and cities in the country. An employee of a fresh Jiangyin restaurant here revealed that before the Qingming Festival, the price of a plate of steamed Jiangdao in the restaurant was as high as More than 6,000 yuan. He said that a plate usually contains 3 Jiang Dao and weighs about 1 kilogram.
Data show that Qingmingqian saury meat contains 16.8 grams of fat, 14 grams of protein and 1.1 grams of phosphorus per 100 grams.
The beauty of the steamed Jiang Dao is that the scales are not removed when placed on the plate. Under the high temperature, the fine scales of the fish body turn into droplets of oil, adding to the deliciousness.
Informed industry insiders said that in Jiangyin this spring, the price of a plate of steamed Jiang Dao in a high-end restaurant is more than 10,000 yuan.
Not only that, a Jiangyin restaurant owner said that before the Qingming Festival, he would worry about the source of Jiang Dao every day, because the competition among various restaurants focused on this fish: "Which restaurant Today, if there are authentic Jiang Dao, whichever one has the best business will do so, because it means that wealthy diners will come." Media reports show that similar competition situations once appeared in Shanghai, Nanjing, Suzhou, Wuxi, Changzhou, Nantong and other places. .
The cost of catching a fish
More than 300 kilograms of swordfish caught by brothers Chen Chusheng and Chen Chugen were sold for more than 20,000 yuan, but the diesel consumed by the two boats The value is more than 4,000 yuan. In this way, each family can only get about 8,000 yuan.
This 8,000 yuan is enough to support Chen Chusheng’s family of three for half a year.
At noon on April 26, on the deck of Su Changyu No. 19037 fishing boat, Chen Chusheng pointed to the river knives divided into three piles of large, medium and small to reporters to estimate his income for the day.
56 Dajiang knives of more than 2 taels, totaling 14 kilograms, 2 taels, 60 yuan per catty; 65 Zhongjiang knives from 1 and a half taels to 2 taels, about 10 kilograms, 15 yuan per catty; 1 tael There are 38 Xiaojiang knives under half a pound, about 4 and a half kilograms, priced at 5 yuan per kilogram.
The biggest catch of the saury season in 2005 brought Chen Chusheng brothers an income of about 1,000 yuan. In terms of amount, the selling price of these 30 kilograms of fish was less than what he sold in late March. For the first time, I gained an income of 2 pounds and 8 taels. At that time, Dajiang Dao was priced at 700 yuan per catty and sold online for more than 1,400 yuan.
This spring, more than 300 kilograms of swordfish caught by brothers Chen Chusheng and Chen Chugen were sold for more than 20,000 yuan, but the diesel consumed by the two boats was worth more than 4,000 yuan.
After dividing it like this, each family can only get about 8,000 yuan. This 8,000 yuan is enough to support Chen Chusheng's family of three for half a year. Half a year later, the brothers will sail into the river again to catch phoenix bream.
Now, another problem faced by Chen Chusheng is that the cost of the boat and net cannot be recovered.
“I regret buying this net.” Chen pointed to the gill net made of white chemical fiber silk and said that it was the most expensive fishing net he had ever bought in his life, worth 6,000 yuan.
For an experienced fisherman like him, owning this special net for catching swordfish was as natural and necessary as a soldier wanting to own a good gun. Four years ago, in order to marry his 30-year-old son Chen Liang, 59-year-old Chen Chusheng decided to give it another try, so he bought a second-hand small steel diesel fishing boat for 40,000 yuan, and at the same time gritted his teeth and added this expensive gill net.
“I have been fishing for Jiang Dao all my life. I know that Jiang Dao has become less and less in recent years, but I never expected that Jiang Dao production has dropped so fast.” 4 years ago, Chen Chusheng bought a boat When the Internet was online, the income for a Jiangdao season was at least twice what it is now.
This time he heard another bad news from a reporter. Since the Yangtze River was closed to spring fishing in 2002, thousands of fishing licenses for river knives have been issued every year and have been favored by fishermen in the first two years. This year, a considerable part was left in the hands of fishery department staff. Taking Changshu City as an example, only 14 of the 29 certificates were issued.
The younger son Chen Liang, who was fishing together, originally planned to inherit his father's business, but now he has changed his mind: there are only a few years left to catch river knives, and the number of phoenix bream is also decreasing year by year, and the fishery has It is unprofitable, so we must seize the time to "enter the factory".
“No young people in the village value fishing anymore. If you fish, you will starve to death.” Chen Liang answered the reporter. He waved his hand and pointed to the factories on the river bank and the sand mining boats in the river.
More than just the Jiangdao is missing
The Yangtze River shad, also listed as one of the "Three Delicacies of the Yangtze River", has been missing in the Yangtze River for five or six years. The process is also that in the past ten years, the number has dropped sharply, the migration route has been shortened, and then disappeared completely.
At the Changshu Fishery Administration Station, which is responsible for managing Chen Chusheng’s fishing boat, the figures revealed by deputy station director Zhang Jinhua are also disturbing: In 1973, the Suzhou River Section produced about 400 tons of river knives, and Changshu alone produced about 400 tons of river knives. 70 tons, while in 2004, Changshu only produced about 2 tons of Jiangdao.
At the Freshwater Fisheries Research Center of the Chinese Academy of Fisheries Sciences, the authoritative research institution for Yangtze saury, Shi Weigang, director of the Resource Research Office, has been unable to provide reporters with the overall annual output data of saury after 2002: " As far as I know, there is no authoritative statistics, because the number is too small, it is difficult to count. "In Shi Weigang's eyes, Jiang Dao is very beautiful, like a pair of silver-white knives, which enter the Yangtze River from the East China Sea at the end of February and early March every year. Cut off the water with a knife and swim upstream. The speed is so fast that it only takes more than ten days to cross thousands of kilometers, reaching as far as Dongting Lake in Hunan. "The swimming of the Jiangdao is like a knight with superb swordsmanship, performing the most magical swordsmanship in the clear sky." A large amount of historical data proves that from the mouth of the Yangtze River to Dongting Lake in Hunan, they have been the production areas of Daolan since ancient times. More authoritative data shows that historically, the fishing output of swordfish once accounted for 35% to 50% of the natural catch of fish in the Yangtze River, and the proportion in the Jiangsu Province section was as high as 70%. “This state has continued until the last century. In the 1970s," Shi Weigang said.
"However, by the late 1980s and early 1990s, there were basically no migrating swordfish in the Hubei river section of Hunan. Two or three years later, there were no more migrating swordfish in the Jiangxi river section. In 1996 Around 1997 and 1998, there was no fishing news in the Anhui river section.
"The Jiangsu river section was not immune. Around 1997 and 1998, first there was no fishing news in Nanjing. Later, there was no fishery news in Zhenjiang and Yangzhou. Also dropped sharply. Now, the migratory route of swordfish has been greatly shortened, and the uppermost reaches of the fishing season can only reach Changshu and Jiangyin in Jiangsu. "Shi Weigang said that the current situation of Jiang Dao always reminds him of another aquatic animal in the Yangtze River - Chinese mitten crab (wild hairy crab). "This kind of crab is also a migratory animal. In 1992, there were still fish in the Wuxue River section of Hubei Province. , in just over 10 years, only the Shanghai section was left, with an annual output of only one to two tons. "Jiangdao may not be as lucky as this crab, because artificial breeding of this crab has been successful. Even if it disappears in the Yangtze River, its population has not disappeared." However, artificial breeding of Jiang Dao has not yet been successful. If we do not cherish it, we may not even be able to preserve the population. "Shi Weigang raised his tone.
Another comparable fish is the Yangtze River shad, which is also listed as one of the "Three Delicacies of the Yangtze River". This fish has been missing in the Yangtze River for five or six years. The process is the same. In the past ten years, the number has dropped sharply, the migration route has been shortened, and then it has completely disappeared.
The "poor fish" has never come back
Qin An'an believes that if it were not for Jiang Dao's talisman. ——After the Qingming Festival, the "bones are as hard as iron", so it is no longer a delicacy, and it may have become extinct
"From the perspective of a fish, the migration of the river knife is very tragic. Think about it, spring is warm and flowers are blooming, and river knifes swim hard into the Yangtze River to fall in love, lay eggs, and reproduce their offspring. But humans have set up thousands of large nets on the river to catch them before they have time to reproduce! ” said Qin An, an associate professor at Nanjing University, 71 years old.
At the turn of the 1970s and 1980s, Qin An, under the leadership of Professor Yuan Chuanmi from the School of Life Sciences of Nanjing University, participated in the earliest Jiang Dao research in China. "This kind of fish has a very violent personality. After being caught in a net, it is not as quiet as other fish, but struggles unwillingly, consumes a lot of oxygen, and dies within a few minutes. We still don’t know whether this poor fish died of lack of oxygen or of fright. In short, it was a death with eyes wide open. "Fisherman Chen Chusheng also told reporters that in addition to regular fishing boats, there are many illegal small trawl nets, deep water nets, plug nets and other nets in the river. Some nets have very small meshes and kill aquatic fish of all sizes. Even fish eggs can be caught.
Qin Anquan believes that if Jiang Dao had not had a talisman - "the bones are as hard as iron" after the Qingming Dynasty and therefore no longer a delicacy, it might have become extinct long ago. . This is a way of life left by nature for the river knife. At this time, the river knife has the opportunity to swim to the spawning ground to complete reproduction.
However, when the eggs turn into fry, they return to the sea. The road was also extremely difficult. Another scholar specifically mentioned the eel spawn craze in 1989. At that time, due to the skyrocketing prices of eels at home and abroad, artificial eel breeding could be extremely profitable, but artificial eel breeding could not be solved for a while. The lower reaches of the Yangtze River are densely populated with nets to catch eel fry.
“The mesh of the eel fry nets is small enough to catch slightly larger granular fish eggs. Since the fishing season for eel seedlings partially overlaps with the time when Eel seedlings return to the sea, countless Eel seedlings were hung to death on eel nets and eventually thrown away as waste.
”
Rhetorical question from grassroots fishery administration staff
Faced with scholars’ views that Jiang Dao fishing should be banned, a grassroots worker at the Changshu Fishery Administration Station asked a rhetorical question: “Thousands of years If we don’t catch the light, will we be able to catch the light in the next 20 to 30 years? "He believes that the main reason for the decrease in Jiang Dao is the water pollution of the Yangtze River.
"Now it seems that our appeal more than 20 years ago has not had an effect. Today, Jiang Dao is still spoken by our crow's mouth. . It pains me because this was completely avoidable. "Qin An'an said that in the late 1970s and early 1980s, five teachers from the School of Life Sciences of NTU studied Jiang Dao for five or six years. At that time, they felt that the number of Jiang Dao was getting smaller year by year. Therefore, they conducted many research on Jiang Dao in various places. Domestic scholars called for the restriction of fishing in the Yangtze River at the exchange meeting, and reported it to the National Animal Association.
The reality is that the relevant national departments have noticed the problem of fish resources in the Yangtze River and implemented it in 2002. During the spring ban, fishing restrictions were implemented on swordfish and anchovies (commonly known as anchovies) in the Yangtze River.
During the breeding season of river swordfish from April to May, the Ministry of Agriculture requires fishermen to obtain a license before fishing.
But Shi Weigang and Qin Anquan both hold the same view: According to the current situation, the fishing of Jiangdao should be banned, rather than restricted. It is so fresh that humans have to temporarily give up this delicious food. "Shi Weigang's reason is that if humans want to use Jiang Dao sustainably, they must find an "inflection point." "If there is no fishing, there are 500 tons of Jiang Dao in the Yangtze River, and humans have caught 250 tons this year, and next year It can recover to 500 tons through natural reproduction, and keeping 250 tons in the river is the 'turning point'.
"The utilization of resources by humans above the 'inflection point' is sustainable utilization.
The utilization of resources below the 'inflection point' is destructive utilization. The result of destructive utilization will be Let this species become extinct. This is a scientific law," Shi said.
Confronted with the views of scholars, a grassroots worker at the Changshu Fishery Administration Station asked: "We haven't caught all the light for thousands of years, but we can catch all the light in the next 20 to 30 years?" He believes that Jiang The main reason for the decrease is water pollution in the Yangtze River.
"How many cities with developed economies can find fish in their inland rivers? Why are river knives almost extinct? Ask the industries along the river to bring those big taxpayers." The fishery official said.
Recently, the Population, Resources and Environment Committee of the National Committee of the Chinese People’s Political Consultative Conference and the China Development Institute jointly organized an inspection team to “Protect the Yangtze River”. Zhang Qi, Executive Director of the China Development Institute who participated in the inspection, told the media afterwards He said that there are small coking and refining enterprises in Chongqing, but in Hubei, Jiangxi, Anhui, and Jiangsu, if you look at both sides of the Taiwan Strait, there are many large-scale steel, shipbuilding, ship-breaking and other heavy-polluting enterprises clustered along the river. What's even worse is that the sewage treatment devices of these companies are almost all "deaf ears", and a considerable part of the sewage is discharged directly into the Yangtze River without treatment.
According to the "China Environmental Statistics Annual Report (2003)", the total wastewater discharge in the Yangtze River Basin that year was 163.9 billion tons, including 72.5 billion tons of industrial wastewater and 91.4 billion tons of domestic sewage.
Shi Weigang’s other position is the director of the Lower Yangtze River Fishery Resources Monitoring Station under the Ministry of Agriculture. He gave an example. In the spring of 1999, in the Zhenjiang section of the Yangtze River, the originally established dolphin monitoring point was affected by the discharge of sewage from a large nearby company. There was no trace of the dolphin. However, at this time, the output of dolphin in nearby Nanjing and Jiangyin had been stable.
“Even if the concentration of pollutants does not kill the dolphin for a while, its long-term chronic toxicity will affect the reproductive system of the dolphin, causing reproductive system malformation and reduced fecundity. In addition, the presence of pollutants in the water body It will also affect the abundance of feed organisms in the waters, which will in turn affect the abundance of the bream, causing the commercial value of the bream to decline," Shi Weigang said.
Fisherman Chen Chusheng also believes that the number of Jiangdao began to decrease after 1973. "After that, factories on both sides of the river were built, and sewage and wastewater were discharged." His son Chen Liang added, He often sees carp, sturgeon and bream choked to death by sewage in rivers near large factories.
Chen Chusheng, who has been fishing all his life, has three meals a day on the boat, and his drinking water is taken directly from the Yangtze River. His most direct feeling is, "The river water used to have a sweet taste, but now the river water is not tasty."
Who will protect the Jiangdao spawning ground
So far, no place along the river has launched a project to investigate the Jiangdao spawning ground. No one knows where the new spawning ground is. No one knows whether these places are being damaged by sand mining ships or various river projects.
He Wei, a teacher at Shanghai Fisheries University, has his own opinion on the main reason for the sharp decline in the number of Jiang Dao - Jiang Dao spawning grounds have been generally destroyed.
Qin Anquan told reporters that one of their major gains during their Jiangdao investigation in the late 1970s was to understand the characteristics of Jiangdao's spawning grounds at that time. "At that time, the spawning grounds of Jiangdao were mainly distributed in river sections in Anhui, Jiangxi, and Hunan, usually in lakes or inland inlets connected to the Yangtze River." Regarding this information, He Weisheng, who has been at the forefront of Jiangdao research in recent years Urgent: "Did you know that these original spawning grounds are basically destroyed now. In order to prevent floods or develop fisheries, local water conservancy projects have been built on those lakes and inlets. Only when people need it, can they be connected to the Yangtze River. Connected gates. Who will meet the spawning needs of river knives? " He gave an example. There is a rapeseed lake in the Anqing River section, which is the traditional spawning ground of river knives. It is now blocked due to flood control, and the migratory river knives are You can't swim in at all. "The key is that domestic water conservancy projects did not take this into consideration in the past and did not build fish passages." Qin An's view is that there are still river knives in the Yangtze River, so logically there must be spawning grounds.
“But so far, no place along the river has launched a project to investigate the Jiangdao spawning grounds. No one knows where the new spawning grounds are, and no one knows whether these places are being mined. "If these few spawning grounds are not protected, further human activities are likely to destroy the Yangtze saury."
If you are. A fish
“When humans expand their living space, it would be better to think more about fish and other animals. Otherwise, the day of punishment will always come.”
4 On the afternoon of September 27, Tang Wenqiao, a professor of ichthyology at Shanghai Fisheries University, listened to the reporter’s explanation of the purpose of his visit and said with a smile: “You can change your perspective and look at the problem from the perspective of a fish.” “If you are a swordfish, you will be interested in humans. I feel angry about many actions in the past 20 years. Think about it, you and your companions swam from the sea to the river, feeling happy and free, because the Yangtze River is your home.
"You and your companions swam upstream. , you like the feeling of water flow. But you find that the water flow in the river has slowed down because many dams have been built in the upper reaches of the river. Then you find that the river water in some places smells bad.
"You swim and swim, trying to find the place where you were born and give birth to your next generation. But a gate blocks your way, or the tributary has a choking smell. You I also found that many river embankments were made of concrete instead of earth, and many of the aquatic plants you liked on the banks were gone.
"More than that, you are not enjoying your meal." The small shrimps and small whitebait you like are very few..." Tang Wenqiao completed his hypothesis and said that this is not just a matter of one river knife, but of all the fish living in the Yangtze River. "Human beings are expanding their living space. Just think more about fish and other animals. Otherwise, the day of punishment will come. Chen Chusheng on the fishing boat said to himself: "I wonder if I will still be able to see Jiang Dao in the Yangtze River on my 70th birthday." "My son Chen Liang said: "I haven't seen the Yangtze River shad in more than 10 years, and I have forgotten what it looks like. In another 10 years, will I also forget what Jiang Dao looks like? ”
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