The depletion of marine fishery resources is a major global problem. "No fish to catch" in offshore waters is forcing more and more countries to turn their attention to distant water fisheries. Since the 1970s, overfishing has brought marine fishery resources into a "dead end", and the arrest of many commercial fish species as endangered is an important signal.
There are many endangered marine creatures that are "eaten" alive by humans. Bluefin tuna is one of the most typical cases.
Bluefin tuna
Survey data shows that in the past 40 years, the number of Pacific bluefin tuna species has decreased by 97%, and the number of Atlantic bluefin tuna has also decreased by 85%. In 2020, the International Commission for the Conservation of Atlantic Tuna (ICCAT) pointed out that if the current fishing quota (2350 tons) remains unchanged, Atlantic bluefin tuna will most likely be overfished by 2021.
Bluefin tuna is known as the "gold in the water" and the "benchmark ingredient" in the sushi industry. It has been enthusiastically sought after by Japanese consumers since the 1960s. Japan consumes 80% of the world's bluefin tuna. Even so, the "appetite" of the Japanese market has not been fully satisfied. Wild bluefin tuna has fallen into a survival crisis in just a few decades, which has a lot to do with the Japanese market.
Bluefin tuna is at the top of the marine food chain . It takes at least 3 years for a bluefin tuna to mature. The long growth and reproduction cycle also means that once the bluefin tuna population resources are destroyed, it is difficult to recover. However, judging from the catch data 10 years ago, bluefin tuna has already been in short supply.
Take Japan as an example. In 2011, Japan took advantage of its high quota and captured 80% of the northern bluefin tuna catch. 98% of the bluefin tuna were juveniles under 3 years old. The smaller and younger catches reflect the sharp decline in the number of breeding groups - a phenomenon that is also common in Australia, South Korea, Mexico, Spain and other countries.
When it comes to bluefin tuna fishing, those countries that have geographical advantages can be said to have tasted the sweetness. Mediterranean and Gulf of Mexico are important spawning grounds for bluefin tuna around the world. Countries along the coast of these two sea areas are naturally "first come, first served" and can easily catch a considerable number of bluefin tuna. Juvenile fish.
Fishermen along the Mediterranean coast have been "dealing" with bluefin tuna for thousands of years. Every spring and summer, when the seawater temperature gradually rises, large numbers of bluefin tuna will migrate to the Mediterranean to spawn, which is a spectacular sight. Local fishermen have accurately grasped the specific migration time and laid "fascination array" traps on the migration path early, waiting for the arrival of fish schools.
Mediterranean fishermen fishing for bluefin tuna
By the mid-19th century, there were more than 100 such traps in Italy and Spain, and tens of thousands of tons of bluefin tuna could be caught every year. This fishing method “takes all sizes”, and many mature broodstock are “caught in one catch” before they can spawn, which undoubtedly accelerates the decline of bluefin tuna resources in the Mediterranean.
In 1864, fishermen in Favignana caught 14,000 tons of bluefin tuna, setting a local fishing record. The bluefin tuna landed at that time were generally very large, with an average weight of about 190 kilograms. However, by 2010, there were only about 100 tuna left that local fishermen could catch, and the average weight dropped to 30 kilograms. The "bluefin fishery" that once brought huge wealth to Mediterranean fishermen was inevitably going to decline. went bankrupt.
Coincidentally, the tragic fate of bluefin tuna also happened in the Port of Jean-de-Luz in France. Port Jean-de-Luz is the largest tuna port in France. From the 1950s to the 1970s, the local area held the nationally sensational "Tuna Festival" every year.
Tuna that just landed in the port
In the summer, the port supplies at least 60 tons of bluefin tuna to the market every day, almost all of which are "gifts" from the Mediterranean.However, since the beginning of the new century, the once famous port of Jean-de-Luz has long since lost its glory. The supply of tuna in two weeks has only been more than 30 tons, many of which are yellowfin .
The "fat meat" of bluefin tuna is so delicious that many countries have begun to breed it driven by interests. This seems to have become an invisible "wealth code". As long as bluefin tuna can be successfully raised, the Japanese market will "accept all orders" - for Australia, Mexico, Malta, Croatia and other countries, this is obviously a good idea "business".
Bluefin tuna breeding and sales model
In fact, as early as 1970, Canadian fishermen began to try to breed bluefin tuna. Since bluefin tuna has a very high metabolic rate and needs to swim constantly to obtain the oxygen required by the body, it consumes a lot of energy and has a low meat production rate. In addition, bluefin tuna only eats live bait and does not eat artificial feed (unless it is domesticated, but the success rate is very low), and the breeding cost is very high. But even so, many countries are still rushing to join the game, for fear of missing out on this "benefits".
At this stage, it takes 15 kilograms of chilled fish to raise 1 kilogram of bluefin tuna, and the feed conversion rate is significantly lower than that of other economic fish - if the same feed is used to raise salmon, the fish meat obtained will be enough 10 kg. From the perspective of meat production rate, cultured bluefin tuna is obviously not the best solution to meet human protein needs, but because of this, its market positioning is also clear-the high-end market.
About 30 million tons of small trash fish are caught ashore around the world every year, and the vast majority of them are used to farm high-value fish, such as grouper, tuna, etc. - This to some extent further aggravates the global Decline of fishery resources.
The staff of the fishery feed bluefin tuna with chilled fish
Many countries regard the breeding of bluefin tuna as a "bonus project", but in essence, this kind of breeding activity only delays the "death sentence" for bluefin tuna - - First, the juvenile fish used for farming are also caught, and are sent to the market and dining tables after 2 to 3 years of farming; second, commercial farming will stimulate fishermen to catch more juvenile fish, and what really works Few countries have attempted breeding and releasing.
Finally, let’s talk about quotas. The current bluefin tuna fishing quota is determined based on two major factors. One is the fishing volume of each country in previous years, and the other is the recovery of bluefin tuna resources in different regions. For a long time, "quotas" have been regarded by traditional tuna fishing countries as the "golden key" to harvesting dividends, and this has triggered many unilateral "demands".
For example, research data from Mexico in 2016 showed that the bluefin tuna population in the Gulf of Mexico showed signs of increasing, so Mexico strongly requested an increase in the quota the following year. Japan and South Korea have also made similar "demands", the essence of which is to catch more bluefin tuna.
The largest tuna trading market in the world (once) - Tokyo Tsukiji Fisheries Market
In short, bluefin tuna is a typical endangered species eaten by humans. Similar tragedies have also happened to other species, such as East China Sea Large yellow croaker, Newfoundland cod. The fish, shrimps, crabs and shells in the ocean are not inexhaustible. If commercial development is not restrained, sooner or later humans will usher in the day when they will run out of fish.
What do you think about the fate of bluefin tuna? Welcome to leave a message and discuss in the comment area!
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