Fish can be raised in fish pens on land instead of in the sea.
This is called land-based fish farming.
Some fish are even being raised in classrooms or the gym at schools.

Unlike fish pens in the sea, these ones are less affected by typhoons and keep out harmful pests, so the fish can grow up healthy.

Mackerel, thread-sail filefish, fugu (pufferfish), and eels are being raised in many regions across Japan.

Fish farming is a process where humans carefully raise fish. But where do the fish come from?

Some fish farmers collect freshly laid eggs and care for the fish all the way to adulthood. Others collect fry from the sea and raise them.

For example, yellowtail/amberjack fry might be born in the seas of Kyushu and then raised in fish pens in Mie Prefecture.

On some fish farms, the father fish, the mother fish, and the baby fish were all born and raised in fish pens. None of them were wild fish in the sea.
This is called closed-system fish farming.

These fish are carefully raised by humans from egg to adulthood so that we can always have a stable supply of fish.
Pacific bluefin tuna, striped jacks, greater amberjacks, red seabreams, and salmon have been raised this way for many generations.

Due to global warming and other reasons, more and more sea urchins are malnourished.
They eat up all the seaweed, causing a barren condition called rocky-shore denudation.
This leads to a loss of habitat for fish and marine life, and the sea begins to turn into a desert.

There are companies where divers catch the excess, malnourished sea urchins, and raise them into edible sea urchins!

Fishing is a job where intuition, honed through years of experience, is essential.
But with fewer and fewer veteran fishers, passing down those skills becomes harder.

These days, smart fisheries using digital technology are attracting attention.
Cameras and sensors gather information about the fish inside the fish pens, and AI gives advice.

This means fish can still be raised properly even with a small number of people!

In a country called Norway, where fisheries technology is advanced, they have giant fish pens where hundreds of thousands of salmon are raised together.

In Japan too, technological development is progressing. There’s a massive fish pen, 50 meters wide, built 3 kilometers away from land. It automatically feeds the fish, and uses computers and cameras to monitor their health.

It allows a lot of fish to be raised even with a small number of people, and the pen is sturdy enough to protect the fish from rough seas, even during typhoons!

To build a society with a steady supply of fish to eat, fish farming technology and fish pens must evolve.

There are now robots that can feed the fish and even clean the fish pens without people, and devices that monitor the health of the fish.

Forty years ago, there were over 400,000 fishers, but now it's said that that number has dropped to around 120,000.

That’s why developing tools that make it easier to raise fish is important for the future!

Watching the fish is only one part of managing a fish pen.
We also have to watch the netting, the sea itself, and much more.
In the past, divers used to go underwater and check, but their numbers are decreasing because many have retired, and the cost of boat fuel is rising too.

To solve these challenges, a hybrid aquatic-aerial vehicle (HAAV) was developed, combining an aerial and underwater drone equipped with sensors and cameras.

It can fly out to fish pens far away, and we can use a computer to see the fish and the sea from land!

By selecting the traits of parent fish carefully and letting those fish mate,
there’s a higher chance of having offspring that inherit their strengths.

This process of mating while gradually improving the breed is called breeding.

The vegetables and fruits that people eat every day have also become tasty and strong through long-term breeding by humans!

By breeding different types of fish, we combine their strengths.
From this fish farming technique, thoroughbred fish have been born!

One example is Burihira, which lets you enjoy the richness of amberjack fat and the chewy texture of yellowtail kingfish at the same time.

Another example is Kuetama, created by crossbreeding the longtooth grouper, which is delicious but slow to grow, with the fast-growing giant grouper, resulting in a fish that grows faster!

The vegetables and fruits we all eat, and even cows and pigs for meat, have gone through thousands of years of selective breeding to make them easier to raise and tastier to eat.

But for fish, selective breeding research only began about 50 years ago.
The fish we eat today might look completely different in the decades to come!