Tuna Fishing in Ōma: A Photo Essay on the “Black Diamonds” of the Sea

Cape Ōma, in Aomori Prefecture, stands at the northern tip of Honshū facing the Tsugaru Strait separating Honshū from Hokkaidō. Across the strait is Cape Shiokubi, some 17.5 kilometers away, and on a clear day, you can see the city of Hakodate.

The Ōma tuna fishing season starts at the height of summer, when the first tuna come through the strait pursuing schools of fatty saury and squid migrating from the Sea of Japan. The season reaches its peak in the autumn, when the fully grown squid start their November return journey, and ends in January of the next year.

This is when the Pacific bluefin tuna is at its peak of flavor, and its unique, coppery aroma is fullest. The rich layers of fat that have grown to keep the fish warm are soft enough to melt in the hands of sushi chefs forming ōtoro nigiri. The market price also spikes, earning these fish the industry nickname “black diamonds.”

It Starts with Catching Bait

After months of back-and-forth, I finally got permission to board a fishing boat. It was a longline boat out of Shitatehama Port at the tip of Cape Ōma.

Longline fishing is a method where a long rope, the mainline, is stretched between buoys with hooked sublines hanging down into the water. These sublines, called snoods, are reeled in at set intervals after waiting for fish to take the bait. Longline fishing is a simple and efficient way of fishing.

Heading out for the Ōma tuna haul. (© Uzawa Akihiko)

At Ōma, the fishing day is split up by method. Daytime is given over to pole fishing, while longline fishing is done at night. The fishing boat I rode set out at 3:00 pm and headed for its fishing grounds at full speed on a sunny afternoon in late September. The wind over the Tsugaru Strait was already chilly, and the captain told me, “The temperature will only keep dropping as we get further out, so take care.”

The deck was so packed with gear and storage cases that there was barely room to set foot. When I asked the captain where I should stand, he pointed at a space about 60 centimeters by 180 centimeters just below the bow. “You stand there,” he said. The full-speed-ahead boat was rolling fiercely, and the captain and I were drenched by the spray. I had nearly lost my nerve before we even got started, and I desperately tried to find some good cheer.

Mackerel for live bait are caught on handlines. (© Uzawa Akihiko)

This boat’s longline fishing begins with live-bait fishing. After three hours underway, we reached the stretch of ocean where our target bait fish are found. That day our boat was after mackerel, but sometimes squid or saury are used, and sometimes fishermen settle for frozen bait or artificial lures.

We started mackerel fishing just after 6:00 pm. I was shocked by the skillful way the crew caught their bait. Three crew members stood on the rocking deck and dropped multihooked handlines over the side without even using a pole. The lines can reel in lots of fish at once.

The bait fish are put into “live-tanks” on the deck with constantly circulated sea water to keep them lively. The fishermen worked with impressive speed, filling the tanks with all the bait they needed in just an hour.

A live-tank filled with mackerel. Fresh seawater is constantly circulated in the container to keep its contents lively. (© Uzawa Akihiko)

Preparation Is Half the Battle

The boat I boarded was equipped with the latest electronic equipment including sonar, a fishfinder, a current calculator, radar, and GPS, letting the captain check every possible detail of the fishing grounds in advance. I was surprised at the level of data collected, from the location where the tuna were gathered to the characteristics of the current boundaries. Clearly, the age when fishing was a matter of instinct and experience is long gone today.

After nine hours on board, at around midnight, we finally approached the tuna fishing grounds. Along the way, the fishermen had worked hard to prepare. When we got to our target, they alighted from the bow onto a GPS-equipped buoy that served as the mainline anchor. It was time to start setting out lines!

It was hard for me to catch the unfamiliar Tsugaru-ben dialect, so I had to focus all my energy on listening to keep up. Suddenly, the captain rattled off a “Come here and look,” in a rare direct comment to me. When I went over, he pointed at the wheelhouse sonar screen. The screen showed a tuna hooked on a line. Everyone broke out into a smile. It wasn’t unusual for boats to return to port without a single fish, so it was enormous luck to get one so soon after setting the line.

That day, the boat set lines in three different locations, ranging in length from one to three kilometers. When the boat was done setting the lines, the three crewmembers ate a quick meal and took a nap while they waited.

Landing Some Big Ones

Reeling in began just before dawn. The boat returned to the location of the first line, using GPS to find the buoy, and began reeling in the line. Mainline lengths are different for each boat, and so the number of live-bait fish differs as well. The length of snoods is apparently a company secret.

The mainline is reeled in using a large automatic winch at the bow, so I was driven back to the stern. And before long, I spotted a glittering fish shape thrashing below the surface. Fish on!

The first catch appeared around sunrise. (© Uzawa Akihiko)

The captain was angrily shouting something that I couldn’t make out through the dialect. I assumed it was something like “Be careful!” or “Watch out!” The slightest mistake could result in a snood getting caught on a hand or a hook piercing a body. Not even veteran fishermen get off easily after such accidents. It was the captain’s job to keep them sharp and careful.

There is nothing to cast a shade on the high seas, so it grows bright even before the sun is high, but work on the rocking boat is still tricky. (© Uzawa Akihiko)

The ship has backup steering equipment at the bow to make sure the boat maintains a fixed position in relation to the longline. The captain operates it in rough seas so the mainline with its hooked tuna can be reeled in at a constant angle. It requires a skillful touch.

As the hooked fish approach the starboard side of the boat, a fisherman drops a device called a shocker, which delivers a high-voltage shock down the lead into the water to knock the tuna unconscious. The now-unresisting tuna floats to the surface and the crew attaches a winch hook to pull it up on deck. The crew lays the tuna out gently on a cushion, like putting a child to sleep.

This is another essential technique to ensure the quality of the meat they take to market. If the fish fights and hits the side of the boat during landing, it could spell real trouble. Although it’s invisible now, when the fish is broken down for consumption, damaged areas of the flesh take on a deteriorated, brownish look earning them the name yake, or “burns.” These yake areas in the pink meat are deemed unfit for sale, so fisherman take extra care when handling the live fish.

The tuna is landed with care to prevent damage. (© Uzawa Akihiko)

Time is the Enemy

If the first round is catching the tuna, the second is handling it on deck. This time, the enemy is time. Crew use a tool called a fish pick to destroy the brain and create a pathway for a wire to remove the spinal cord. They then quickly saw the motionless fish’s tail off to check the meat.

They cut the aorta behind the gills and use seawater to flush the blood from the body. Next, they push a knife in through the gills to remove the organs, and sever the intestine from the lower abdomen. They then remove the nerves, wrap the fish in a waterproof covering, and chill it in a pool of iced seawater. All this is done in a mere 10 minutes, with the crew working at an astonishing speed.

The tuna’s tail is quickly removed to check the meat. (© Uzawa Akihiko)

Bleeding the fish is a battle against time. (© Uzawa Akihiko)

The wrapped tuna is submerged in ice water. (© Uzawa Akihiko)

The speed at which they carry out this process can completely change the tuna’s flavor, color, and aroma. Performing this vital processing quickly guarantees freshness and flavor, which again influences the sale price. Shortcuts are not allowed here.

In the industry, Ōma fishermen’s processing skills are legendary, and they far outshine any of the other ports fishing around the Tsugaru Straits. It seems this is how Ōma has managed to keep its name as the absolute top of the tuna fishing industry.

There is no room to stand on the narrow deck with all the equipment and the landed tuna itself. (© Uzawa Akihiko)

While the crew is processing the first tuna, the next is being reeled in. Even though the landed tuna are being constantly rinsed with seawater, the smell of blood soon sweeps across the deck. It truly does feel like a battlefield.

With such brutal work on the boat, Ōma’s tuna fishermen risk life and limb at times. Fishermen must always remember the old saying, “Hell is only a thin plank away,” as they contend with the overwhelming might of the sea with every catch. Their goal is not simply to earn a living. Theirs is the pride of the hunter, the pursuit of one of the greatest fish in the sea in a struggle with the power of nature.

The day’s catch was 10 fish. After the fish are offloaded and weighed at Ōma port, they’re once more put into ice water to await delivery. (© Uzawa Akihiko)

(Originally published in Japanese with the cooperation of Ishiji Toyosu Market Intermediate Tuna Wholesaler. Banner photo: Fish are bled while the mainline is reeled in. The deck takes on the air of a battlefield. © Uzawa Akihiko.)