Press: Cod has been a famous edible fish species since ancient times, which was only popular in Europe and the United States in the early years, and later spread to Asia and was widely welcomed. Steamed cod fillets, garlic-flavored silver cod, cod shreds... They are all cod delicacies that have been passed down in our country for a long time. In A Fish That Changed the World: The Cod Past, author Mark Kurlansky uses cod as a historical entry point, recounting a large number of characters and stories associated with it. Cod is not only a delicacy on the table, but also a participant and witness to human social life: in the 18th century, cod made New England from a remote and barren colony to an international trade authority; New England has a long tradition of cod trade between new England and the French Caribbean colonies; the strange "cod war" between European countries lasted for many years without casualties...
On the other hand, the survival and change of cod species also bear witness to the vigorous appetite and endless greed of human beings. Cod is a very viable benthic fish, easy to survive, easy to hook, strong reproductive ability, which also makes cod seem to be born with the mission of meeting human appetite, nutrition and energy needs. In the 19th century, the prolific nature of cod almost reached a frenzy. Dumas once imagined: "If all cod eggs can hatch and grow up smoothly, then people can step on the back of cod and cross the ocean." "In 1970 alone, the global cod catch was as high as 3.1 million tonnes. Just 30 years later, that number plummeted to 890,000 tons. The World Wildlife Conservation Fund noted that if the governments of the countries concerned do not take measures to control cod fishing, cod resources will cease to exist after 15 years.
On the cover of the Chinese edition of "A Fish That Changed the World: The Cod Past" is the following sentence: "They are forever surrounded by a group of large-mouthed predators, that is, humans— animals that eat everything and are more greedy than cod." The Irish poet Yeats once wrote a poem called "The Old Fisherman's Meditations": "The cart full of blue fish creaks, and the fate of the fish is deeply sad." I was an ignorant child then, and now I can't see fish coming and going with the tides. "Eat and cherish, and fish and protect, otherwise our descendants may only see the cod in the book and imagine the delicious taste of the cod."
<h4>A Fish That Changed the World: The Cod Past (excerpt</h4>).
The cod will be back, the fishermen say
Under pressure, the minister had to end the ban on Newfoundland's waters
—Front page headline of Toronto's Global Post, October 5, 1996
Newfoundland residents talk about "when the cod comes back," but few dare to ask, "What if not?" "If they don't come back, does that mean something happened to the ocean?" "Should commercial fishing continue?" Sam firmly supports the idea that the cod will come back, arguing: "It's inevitable that the cod will come back." ”
Scientists aren't so sure. Ralph Mayo points out that there is currently no formula that can predict how many fish (in scientific terms, the number of organisms per unit area) or how long it will take to restore the population to its original number. Nature can do miracles, but it can also bring disasters. In 1922, cod populations in the waters off Iceland inexplicably produced many juvenile fish. So, although both British and German trawlers fished here, a decade later there was still a considerable stock of cod in Icelandic waters. "There are so many changes in nature that the current phenomenon may be caused by winter storms, when the wind blows the juvenile fish far away from the fishing grounds." Mayo said. The only thing that is certain is that "when the number of cod is zero, they are unlikely to produce offspring, but we do not know how large the population is to successfully reproduce." ”
This optimistic claim is supported because other countries can recover quickly after heavy cod harvesting. In 1989, the Norwegian government learned that its cod stocks were on the verge of extinction and immediately severely restricted the development of the fishing industry and reduced the size of fishing vessels. This policy has led to the unemployment of a large number of fishermen, fish processing plant workers and shipbuilders, and in the northern regions using Finnish marks, unemployment rates have reached an unprecedented 23%. However, as a result of these measures, cod catches remain considerable and large mature females have been found within cod populations. Because of this, the cod population maintained a steady development and began to increase after a few years. Getty, who works for The Norwegian Seafood Export Council, describes the situation in Canada this way: "I guess those government officials didn't dare to stop workers. "It was courage and good luck that allowed Norway to get out of trouble, and of course it was inseparable from the fast-growing cod population. In the autumn of 1992, the Norwegian government estimated the cod population in the Barents Sea, and the host was as surprised by the final result as in 1989: after two years of reproductive peaks, the cod population has grown again!
In 1994, the Canadian government announced that the fishing ban was likely to last until the end of the 20th century. Politicians began to move around to speed up the lifting of the ban. But in Canada, even if all goes well, it will take about 15 years to rebuild the cod population. A healthy population needs several mature females that are large enough, and in northern fisheries, it takes about 15 years for a fish to grow and mature. It's hard to imagine Canada stopping fishing for cod for so long, which means that people won't be able to eat cod for almost an entire time. Ross, who works at St. John's Memorial University, cautions that political pressure may not wait for the cod population to recover before the fishing ban dies. As a pioneer in calling for a fishing ban, Ross said: "I am not optimistic about whether the cod population can return to its original level, if there are 300,000 cod today, people will be eager to catch them all." ”
Later, the government announced a policy of cyclical food fisheries, where locals could catch their daily cod on a specific weekend. Cod will be transported in trucks every few weeks, and people can also buy it on specific weekends. Local politicians have criticized the food fishery for being implemented for too short a time each time. Lewisport's mayor said some people worked on weekends and she wanted to "give everyone a chance."
In October 1996, Fisheries Minister Mivlin said in an article in the Global Post that fishermen at the Department of Fisheries Conservation reported that cod numbers and sizes were increasing: "Cod is fat and healthy, and it is certain that the cod population has stopped decaying." This conclusion is not at all in line with the observations of Sam and his Port Petty colleagues, but they are only six of the 400 fishermen of the Newfoundland Fisheries Conservation Service. A closer look at The Mivlin data shows that the good news comes from southern Newfoundland, where the waters are warmer and the fish grow faster. In fact, cod populations are relatively independent compared to cod populations that inhabit other Newfoundland waters, Labrador and shore areas. This is what Ralph Mayo calls a "cognitive problem."
A few weeks before Mivrin's statement, Ross said: "We found 15,000 cod in the southern bay, so everyone said cod was back." But wait a minute, there were 1.2 million cod populations a decade ago. ”
Some people think nature should be helped. When the Norwegian fishery was at a critical juncture, the government invested a lot of money to experiment with cod farms. Raising cod is more expensive, so once the wild population returns, norwegians will immediately lose the benefits of operating farms. But farmers have successfully transferred wild juveniles into cages and raised them into fat adults. Cod has even been trained to swim back when fed. "The rearing of juvenile fish is where we are ahead of others." Getty said. Norwegian-farmed cod are very fair in color because they are "cleaned" before being transported to the market, in the same way that lobsters are handled, starving the fish for a few days. Another advantage is that they can be shipped to the market alive, which is the key to Martin's proposed plan.
Cod farming is a new technology, while salmon farming has matured, but Martin asserts that cod will be easier to farm. Salmon's scales are fragile and susceptible to virus infection, while cod can tolerate artificial tossing and are highly resistant to disease. In addition, salmon do not like to be crowded in cages, and cod have a social structure of swarms.
From mussels to salmon, the fishing industry is widely farmed, and the industry is growing every year. After experiments in Port Petty, Martin put the cod in wooden cages and fed them with mackerel, bluefish and woolly fish, and in this way he bred fine cod. But when he was off the fishing ban, he was in debt for $1 million because he had no business. The success of fishery farming lies in the fact that it is fed with crushed bait, which can reduce operating costs compared to the method of fishing with bait in the wild. For example, adding pigment to the feed of salmon can get pink salmon meat, while salmon in the wild are pink flesh because of eating crustaceans. Just as domestic pork is no different from wild boar meat, cooked farmed cod tastes very similar to wild cod.
In addition to gourmets, scientists are also very concerned about the cultivation of cod. The growth of captive cod has been remarkable, and they are much larger than the fish of the same age in the northern fisheries. Wild cod can triple every year, while farmed cod can quadruple. Since body size determines fertility, raising cod and releasing them appears to be a way to rebuild populations. In fact, however, this is a dangerous thing.
The idea of putting farmed fish into wild populations frightens scientists because humans don't arrange fish to reproduce according to natural selection. Farmed cod are likely to be unable to resist disease, do not know how to escape predators, lack hunting skills, and may not be able to make antifreeze proteins due to poor structures that sense temperature, detect changes in water temperature and send messages of "migrating to the coast to spawn". This cod simply cannot survive in nature, but they may be able to live in cages. If they also have some characteristics that are particularly suitable for farming life, then this disabled fish is likely to be very active in the fish school and even have an advantage in the population. Once mated with wild fish, they pass on bad genes to the next generation.
Christopher Tegat, a fisheries marine geologist at Dar hughes University in Halifax, once likened farmed cod to purebred dogs and thoroughbred horses: "Most purebred dogs have genetic diseases with poor hip joints, and if you examine each thoroughbred horse closely, you will also find that they have broken a leg, which is the result of human selection." Trying to breed a thick-haired dog that is good at swimming can cause problems with its hip joint. If the dog breeds in the wild, it will produce wild wolves with hip problems. ”
The effects of fishery farming on biogenetic characteristics are now unclear. We simply assume and hope that the fish in the cage never escaped into the wild and did not blend into the local population. But such accidents have happened, and to make matters worse, some people farm juveniles in order to release them to increase the number of wild populations. By 1996, new England salmon farms had released many fry. It is estimated that only 500 Atlantic salmon also have the genetic diversity of the Wild Population of New England.
The diversity of genetic traits is the main feature of the survival of species, because only in this way can organisms adapt to the challenges of life. Scientists don't know whether the few remaining cod populations in the north still retain all the genetic traits that have accumulated in the population gene pool over millions of years, but they can only hope for it. Assuming that genetic differences persist in the population, Tegat argues, then, in order to maintain genetic diversity, farming methods "should be as natural as possible." Because only careful selection of spawning sites can improve the survival rate of juveniles, and at the same time greatly help the maintenance of the population." This is how wild cod choose their spawning grounds.
Overfishing is a growing global problem. According to the results of a follow-up survey by the Food and Agriculture Organization of the United Nations, 60% of the world's fish species have been classified as "fully utilized", "overused" and "exhausted". Tuna on the Atlantic coast of the United States has declined significantly, but Gloucester fishermen still believe they have a good harvest and use this to refute the claim of overfishing. The group of sailfish in the middle of the Atlantic is shrinking; shellfish and salmon are disappearing from the Caribbean; the ancillary magenta seabream from shrimp fishing in the Gulf of Mexico is nearly extinct due to commercial fishing; the Peruvian anchovy is plummeting; the blue cod is disappearing from russia's Sea of Okhotsk; and 90 percent of the world's fisheries within the 200-mile economic exclusion zone have been closed, leaving fishermen to travel deep into the ocean in search of new species. The ecology of the deep sea is not well understood, but the water there is at a low temperature all year round, and the fertility of fish can be very low. After the establishment of the 200-mile economic exclusion zone, raw orange fish was introduced to the world market and became very popular. The fish come from the deep sea near New Zealand and are caught at 5 tonnes an hour. In 1995, the fish also disappeared.
The collapse of the Soviet Union undermined many fisheries agreements. Russia became the dominant cod fishing country, and in russia's Barents Sea fishery, cod is almost equal to cash. Canada buys processed Russian cod from Norway because russian fish in the Norwegian market is already flooded.
Because the Atlantic Ocean has long been overused by Europeans, fishing began to shift to the Pacific. Large Japanese, Russian, U.S. and South Korean fleets, as well as China, which has not participated in international cooperation in the past, have significantly increased their fisheries capabilities.
The idea of replacing Atlantic fisheries with Pacific fisheries has been around for a long time. Pacific cod was also one of the reasons the United States bought Alaska from Russia in 1867. But the main market is far away, and Pacific cod is not as successful as Atlantic cod. Despite this, 500,000 Pacific cod were caught ashore in 1890. In 1897, the American scholar Butler mentioned in his book that with the development of Pacific fisheries, the competition between the United States and Canada over cod fisheries would cool down, and the United States would have no choice but to ally with Canada.
Compared to Atlantic cod, the meat of Pacific cod is not very valuable. They don't migrate, live to last no more than 12 years, and more importantly, they don't catch as much Atlantic cod. As a result, the cod has become a fishing target in the North Pacific, and Gordon employees call it "the cod of our time." Gradually, overfishing of the cod not only affected its own population, but also the number of seals and a variety of seabirds that fed on it declined dramatically from the mid-1970s.
Marine ecology is very complex and interlinked. In order to supply Denmark with fish mud as fuel, large offshore factories overfish mackerel and other small fish in the North Sea, forcing cod and seabirds to starve. In 1986, a large number of seals swarmed south in the North Sea, eating up all the fish off the Norwegian coast, and they starved like this because of the overfishing of the woolly fish. Fishermen called for seal hunting to keep the North Sea from seals. In 1995, Norway and Canada revoked the seal ban because the growing number of seals were eating cod.
In the late 1950s, environmentalists began to pay attention to operations seal hunting in Canada. Due to the high price of seal skins, large numbers of seals have been hunted off the coasts of Newfoundland and Labrador. This is a group of amateur hunters who come in helicopters, are rude and have no skills. In 1964, a film sparked a wave of fury among animal activists around the world. Filmed by Montreal-based production company Altek, the film recounts the struggle of a skinned seal to survive. Although the Skinners had accepted remuneration from the production company, and the other two hunters had later become partners in filmmaking, international opposition did not subside. In 1983, under strong pressure from environmental groups and the European Common Market's refusal to buy, Canada finally issued a decree banning traditional seal hunting in Newfoundland and Labrador.
The reopening of the seal hunt in 1995 was inevitably condemned by domestic and foreign environmental defenders and animal rights groups, who claimed that there was no scientific basis for the seal hunt, and some even denied that seals ate fish. Before the seal conservation movement became a sensation, Newfoundlanders knew seals ate cod. The trademark of G.H. Garton, Newfoundland's largest soda company, is well known, with a picture of a seal standing on the ice floes next to it: "Cool off!" "In the less political 19th century, this seal had a cod in its mouth!
According to the Canadian government, the ban on seal hunting doubled the number of saddle seals to 4.8 million, a figure that would have become 6 million in 2000 if the ban had not been lifted. Seals ingest large amounts of fish, and they are very wasteful, so they are particularly unpopular with fishermen. Like most predators in North America, grey seals, spotted seals, and saddle seals don't like to handle fish bones, ripping open and eating the cod's softest belly, and much of the meat left is wasted. "Seals don't need to eat a lot of cod to maintain a strong physical strength." Ross said. "Their waste doesn't mean we should declare war on them, though, but we have to control the seal population." A Canadian journalist remembers Brigitte Bardot posing on ice floes during the 1977 seal conservation campaign, and he felt that the French actress should now hold a cod.
Since species within the biosphere are interdependent, the fundamental question is whether other species (not just seals, but also phytoplankton, zooplankton, scaly fish, seabirds and whales) will spend 15 years waiting for cod to return? Nature may be more impatient than politicians. "In any case, as long as you continue to work hard, there will be a way out, and nature may have other ways to solve it." Ross said. If the number of species preyed on cod increases sharply as a result of the decline in cod, other species will migrate and replace the cod ecological status, and if the invaders succeed, there will no longer be enough food in the environment to support the survival of the cod population. Some biologists worry that small sharks such as stingray rays, rays and horned sharks have invaded.
Ross, who studies northern fish by the sea, said: "Fishermen have found many peculiar phenomena that show that something is wrong. "Cod are maturing earlier than before, they are getting smaller, and fish under four years old are starting to spawn. This is not surprising, though, because the laws of nature always move in a direction conducive to the survival of living things, and when a species is on the verge of extinction, they usually reach sexual maturity earlier. But Ross also said that based on observations, cod spawn at minus 1°C, so it can be speculated that cod may have migrated to warmer seas to spawn. Fishermen constantly report anomalies, such as fish stocks in places that have not been seen before, in waters of different depths and temperatures than before, and at different times of the year.
While the situation is very chaotic, Ross's research suggests that northern fish stocks have stopped migrating. Cod typically undergoes a 500-mile seasonal migration, and Ross believes that after 1992, the surviving cod will settle offshore. He doesn't know the cause of this phenomenon, but speculates that the larger, older fish that used to lead the way in schools no longer lead the population; in addition, cod may have migrated in search of food and spawning space, but as the population shrinks, this demand does not exist.
Whatever measures are taken, the biggest obstacle to the restoration of the Newfoundland cod population remains humanity. As long as they blame their natural reward – the cod killings – Newfoundlanders seem to be able to accept any reason. For example, a Canadian journalist once published an article pointing out that the disappearance of Newfoundland cod is the same time as the recovery of the Norwegian cod population, so the northern fish must have moved to Norway as a family.
Human beings are accustomed to separating nature and biological evolution from their own activities, but although nature and human society seem to be different, human beings are still part of the natural world. If humans become ferocious predators, it is also the result of evolution. When cod and haddock or other species cannot survive because of human hunting, other more adapted species will take their ecological place. Nature is the most standard pragmatist, always stubbornly manipulating everything in the world according to a certain law. The example of the tenacious survival of cockroaches can prove that the things that nature prefers are not necessarily the case for humans.
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