A sushi tycoon from Japan has paid a record £2.5 million for a single Atlantic bluefin tuna in an infamous Tokyo fish market auction. What are the resulting implications for this endangered species?

Japanese businessman Kiyoshi Kimura paid a record fee to land the first Atlantic bluefin tuna of the year sold at the Toyusu fish market in Tokyo. The auction took place on 5th January and the price of £2.5 million ($3.1million) was significantly more than the previous record set six years ago. The tradition of bidding on the first, and often largest, tuna of the year is longstanding and is seen as a great honour among the fishing community. Although this is a one off price the average price of the meat in Japan has drastically increased from £31 per pound in recent years to over £157. Unfortunately bluefin tuna stocks have decreased by 96% since 1950 and due to serious overfishing, particularly in Japan, they are now listed as endangered by the WWF. The tuna will be served as sashimi to diners at a popular sushi restaurant in the coming weeks. But if things don’t change it might not be long before it disappears from their dinner plates forever.

Who is the ‘Tuna King’?

Kiyoshi Kimura, the self-styled ‘Tuna King’, is the owner of Sushi Zanmai a popular restaurant chain in Japan. He is the man who paid the record fee of £2.5 million to land the 278kg fish eclipsing his own record of £1.4 million set in 2013. The sushi tycoon is a frequent attendee of the historic auction and has walked off with the prize tuna multiple times including a six year stretch at the start of the decade. As well as it being an honour for him to buy the first tuna of the year it is also a show of strength to his competitors and helps advertise his business to the public. Last year Mr Kimura lost the auction to a competitor which seems to have made him desperate to regain his crown this year no matter what the cost. When he was interviewed after the auction by Japanese news outlet NHK he claimed “the quality of the tuna I bought is the best” and said “I hope our customers will eat this excellent tuna” but went on to admit “the price was higher than originally thought”.

Why is the price so high?

So apart from Mr Kimura’s desire to win back his honour what caused this particular tuna to go for more than $5,000 per pound. One reason is that this year’s auction was the first to take place at the Toyusu market after traditionally being held across town at the Tsukiji market, which was closed down to make room for parking for the Tokyo Olympics next year. Therefore it was not just about winning this year but also throwing down a marker for the years to come. Another reason may be the size as this particular tuna was one of the largest ever to be sold at the market weighing more than the equivalent of three fully grown men. However historically size has very little correlation with price at the auction, even though Kimura claims the fish will serve over 12,000 portions to customers, he will never come close to making his money back. Unfortunately the most likely reason the price is so high is due to the fact the Atlantic bluefin population has crashed due to overfishing and are becoming so rare.

From cat food to million dollar delicacy

Japan are today the biggest fishers and consumers of Atlantic bluefin tuna in the world but it hasn’t always been so popular there. In the early 20th century the Japanese people disliked the metallic taste of tuna meat often fermenting it or marinating it in soy sauce to get rid of the taste. More often than not the meat was just used to feed their pet cats. However that all changed in the 1960’s and 70’s when sushi became popular in America and with it the introduction of the more fatty and tasty cuts. In the following decades the result was a 2000% increase in catch rates in the Western Atlantic and a price increase of over 10,000%. This led to unsustainable overfishing that has resulted in a 96% decrease in their numbers since 1950. Unless serious action is taking in reducing fishing pressure and allowing populations to recover it is likely that the species will be driven to extinction.

Not your everyday fish

While the Atlantic bluefin tuna, Thunnus thynnus, are now associated with astronomical prices there is so much more to them than the values we have placed on them. They are incredibly fast swimmers capable of reaching speeds of 43mph making them not just one of the fastest fish species but one of the fastest creatures in the ocean. This is mainly due to their high concentration of white muscle compared to red muscle which allows for quick sprinting bursts compared to long distance endurance. They are also aided by a strong cresent shaped tail, a streamlined body and can even withdraw their pectoral and dorsal fins into slots to reduce drag. But it is their white muscle that is the reason why their meat is so different and sought after.

Bluefin tuna are also unique because they are able to maintain a warm body temperature of between 20-24oC. This is extremely rare in fish who are mainly exothermic, meaning cold blooded, and is due to their white muscle that generates heat but also aided by an extremely efficient vascular system. Finally due to their sprint swimming and warm bodies they require large amounts of oxygen to generate energy. They achieve this with an incredible gill system that has up to nine times the surface area of similarly sized fish. They also eat constantly feeding on anything from smaller fish to squid and occasionally even kelp. The largest ever recorded bluefin tuna weighed in at an incredible 678kg, well over twice the size of the price record breaker bought this year.

Japan in hot water

This year’s market auction in Toyusu has increased the spotlight on Japan who were already under heavy criticism from conservationists and world governments. It comes less than two weeks after Japan announced it would be leaving the International Whaling Commission (IWC) to restart commercial whaling in their waters for the first time in over 30 years. Their announcement may not be as damaging as it first appears due to its complex nature but nevertheless has been widely condemned by the international community. You can read more about Japan and commercial whaling here. As a leading country in so many ways it is a shame that Japan seems to fall short in terms of marine conservation. Their situation highlights the need for international co-operation to help protect marine species rather than a ‘go it alone’ approach.

Hope in the UK?

Atlantic bluefin tuna used to be seen quite frequently in British waters, in the 1930’s they were commonly caught by big-game fisherman but by the 1990’s they had all but disappeared from our waters. However in the last five years sightings of the warm blooded fish have increased significantly in the UK and other parts of Europe in particular the Nordic Sea. This has led to some people speculating that populations are on the increase but unfortunately that is not the case. The main factor behind the increase is a shift in ocean currents, known as Atlantic Multidecadal Oscillation (AMO), which has warmed the waters surrounding the north of Europe. This means rather than an increase in bluefin tuna numbers it is just a redistribution of some of the remaining individuals.

Is there really honour in hunting a species to extinction?

Japan is by no means the only country that is guilty of overfishing but their high consumption of Atlantic bluefin tuna has put a huge strain on these magnificent animals. While the tradition of bidding on the first tuna of the year may be important to the Japanese fishing community, it encourages an unsustainable practise that could wipe out their prize species. They may argue that it is a one off event but there is strong evidence to show that the average price of tuna meat rises and falls in relation to the auction prices. As a result the current record prices are an extremely worrying sign for the tuna’s survival and there may be no way of telling how it will affect them until it is too late. It may be considered a great honour for businessmen such as Kiyoshi Kimura to win the Tokyo auction but if it leads to the end of a key ocean predator such as the bluefin tuna is this really an honourable tradition?

Links

https://www.smithsonianmag.com/smart-news/threatened-bluefin-tuna-sells-record-3-million-new-years-sale-180971181/?fbclid=IwAR2YIo_8D8Ep4XTFid08Oq3WbaaMdbou1hAv-VKcRSY06K7VxvxzwrHxg1Y

https://www.bbc.co.uk/news/world-asia-46767370?fbclid=IwAR0g1ZOr6a_bWP8bhGj-G_IEi2PDilAe8BKDl76Ccf5NiT0F66Y9grqYAGM

https://www.bbc.co.uk/news/science-environment-46738175

https://www.nationalgeographic.com/animals/fish/a/atlantic-bluefin-tuna/