Why Can’t Octopus Be Farmed Amid Rising Prices?

The continued shortage. The price of octopus is now double what it was 10 years ago!

The price of octopus is soaring. With a continued shortage of octopus, a survey by the Ministry of Internal Affairs and Communications shows that retail prices have been rising year by year, and by November of last year, the price in Tokyo’s 23 wards reached 534 yen per 100g. This is double the price from ten years ago. Now, it’s comparable to the price of tuna or beef.

Some takoyaki shops in Osaka’s Dotonbori area are selling a plate of eight pieces for over 1000 yen. That’s more than 120 yen per piece! It’s no longer a casual snack. Due to the rising prices of octopus and wheat, takoyaki shops across the country are crying out, with some seriously considering going out of business or even making takoyaki without octopus.

“The octopus we buy for experiments has also become more expensive. It used to cost 1,500 to 2,000 yen per kilogram, but now it’s 3,000 to 5,000 yen. It’s tough,” says Professor Nobuhiko Akiyama of Tokai University’s Faculty of Marine Science.

Together with several universities and companies, he is working on a land-based octopus farming project, aiming for commercialization by 2030. If successful, it would be the world’s first.

With just five years left until commercialization, can we see the light at the end of the tunnel?

“Not yet. There are still many challenges,” says Professor Akiyama.

 

Parent octopuses fight each other. While it’s now possible to avoid this with octopus shelters

 

To successfully achieve complete octopus farming, there are three major hurdles to overcome.

Complete farming means that octopuses, artificially hatched, lay eggs, which are then nurtured and hatched again. Currently, the process involves allowing wild-caught parent octopuses to lay eggs, which are then raised.

The first hurdle is the need to keep a large number of parent octopuses. The second hurdle is figuring out how to feed the planktonic larvae that have just hatched from the eggs. The third challenge is preventing cannibalism once the plankton grow and settle on the bottom.

Octopuses are highly territorial. When placed in a tank, they often start fighting, and the weaker octopuses will end up leaving the tank and dying. The solution was to create octopus pots, but sometimes one octopus would dominate two pots, making it ineffective. Professor Akiyama and his team then thought of a tower-shaped shelter, but although octopuses would enter the first level, they would not go beyond the second level. One day, however, the octopus became agitated and knocked the shelter over, turning it into a long, horizontal shelter resembling a row house.

“Then, for some reason, the octopuses started using it.”

With this method, they were able to house 100 parent octopuses in one tank, overcoming the first hurdle. However,

“When farming fish like yellowtail, we mix soybean or wheat-based feed. But octopuses only eat raw food. Currently, we are feeding the parent octopuses with artificially made food using frozen crabs, but the cost of ingredients is high, and at this rate, one octopus would cost tens of thousands of yen. This makes it impossible to bring octopuses to market.”

Even after they settle on the bottom, they die one by one. The reason is unknown

The octopus larvae, just after hatching, drift in the water as plankton for about a month before settling on the seafloor and growing.

As for the second challenge, which is the food issue during the plankton stage.

“The newly hatched octopus larvae (in their plankton stage) drift in the water, and if food doesn’t happen to come to them, they starve to death. In nature, most of the larvae die for this reason.

Even if artificial feed is made and given, it falls to the bottom, so they can’t eat it. To solve this, we created a device to stir the water in the tank, which allows the food to float up so they can eat it.”

Although feeding has become possible, the nutritional aspect is still insufficient. As a result, they haven’t been able to grow to the point where they can settle on the seafloor.

“In fact, we still don’t know what octopus larvae eat in the wild. While we’ve been able to feed them, we don’t know the ‘necessary nutrients.’ Even though we give them food, they continue to die.”

The second hurdle has not been overcome yet.

The third hurdle is how to prevent cannibalism after the larvae settle on the ocean floor.

“We were able to improve that significantly by creating shelters for the young,” he says.

However,

“They still die off one by one. Again, we don’t know the reason.”

There are still many unknowns. It certainly seems like a difficult road ahead. One might worry whether they can commercialize it by 2030.

“When you figure one thing out, things can move forward all at once. We’re currently eliminating possibilities one by one to find the solution. I absolutely want to commercialize it by 2030.”

▼Nobuhiko Akiyama, Professor at the Department of Fisheries, School of Marine Science, Tokai University. In addition to land-based octopus aquaculture, he is researching breeding techniques, feed development, and rearing technologies for various species such as bluefin tuna, cuttlefish, shrimp, and abalones.