In a small town in Catalonia, a group of fishermen toils from dawn to dusk, searching for red prawns deep in the sea.

At 5:30 a.m. on an overcast morning last June, Miquel Fortuny was preparing breakfast at his house in Palamos, a seaside town about 60 miles up the coast from Barcelona. A well-built man with tanned forearms, Fortuny, 53, moved quietly around the room as he set out two muffins and a glass of milk. It’s the same breakfast he’s had every day since he started fishing nearly 40 years ago, he told me in a stage whisper, careful not to disturb his wife and two daughters, still asleep upstairs.

When Miquel finished breakfast, we left the house and walked toward the harbor, the heart of this 18,000-person town. The sun was barely visible in the overcast sky as thin strips of pale blue and pink formed over the horizon. The yellow glow of street lamps still lingered as we made our way downhill. Miquel’s family and ancestors have worked as fishermen in Palamós for almost 120 years.

Miquel himself started fishing with his uncle when he was 16 years old; four years later, he inherited his uncle’s boat, the same one he captains now, the Mandorri. “As teenagers, my friend and I used to make our own boats from an old door and engine,” he recalled.

Meet the queens of barnacle hunting in Spain

The Mandorri is one of 16 boats in Palamós that fish for “Gamba de Palamós,” the renowned local prawns that travel from this small fishing town in Catalonia to the finest restaurants across the region and the world—from El Celler de Can Roca, one of the world’s top establishments in nearby Girona, to luxurious eateries in Washington, D.C., and Hong Kong. Due to the high concentration of carotenoid pigments in the plankton they feed on, Palamos prawns emerge from the sea a blazing red, starkly different from the dull gray-blue of most shrimp species.

Prized for their vermillion color, firm texture, and sweet flesh, Palamós prawns can fetch more than 200 euros—about $230—per kilogram around Christmas and the New Year. But few people are aware of the long journey that these crustaceans make—or of the difficult lives of the fishermen who bring these prawns from the depths of the sea to the dining tables.

Xavier Fortuny at the helm of the Mandorri.

As a result of a boom in mass tourism in the 1960s, many of the villages in the region no longer have active ports. By 2014, just 1.2% of the Catalan population worked in agriculture and fishing; in Palamós, the number of fishing fleets continues to dwindle each year. Yet the town’s famous red prawns are still a source of tremendous profit, accounting for about 5% of the catches in Palamós but nearly 30% of profits.

As we walked down the hill, a short, lean man with glasses appeared around the first corner, an early morning cigarette dangling from his mouth. The two men mumbled a greeting. It was Xavier Fortuny, Miquel’s younger brother and the boat’s second-in-command. He passed a red plastic binder to Miquel that contained the ledger of the previous week’s wages for their employees. Unlike most people in Spain, fishermen are paid weekly.

These Americans farming Russian caviar say it’s as good as the wild stuff

By 6 a.m. the port was buzzing: workers in yellow overalls stepped on and off their boats carrying loaves of bread, newspapers and equipment while shouting greetings and orders at one another. The Mandorri—a 93-foot trawler freshly painted with red and white—sat perfectly still in the gray water.

“I spent 500 euros on games and toys at the town fair this weekend,” said Lluís Ramirez, 54, who has been on the Mandorri since he was 15 years old. “No way!” a stocky young fisherman shouted back as he cut away loose strands from a rope. He was Miquel “Miquelito” Jiménez, 31, the youngest of the crew. “You’re too cheap to spend that kind of money,” he said. The others laughed as they checked the gear to make sure everything was in order.

Prawn fishermen in Palamós spend five days a week at sea, handling large machinery under the beating sun in the summer. When the prawns migrate to deeper waters during the winter, they take month-long expeditions to hunt for bluefin tuna south of the Balearic Islands some 250 miles away from Palamós. Like fishermen everywhere, they leave port each morning knowing neither how much they’ll catch nor how much they’ll earn.

Nearly 15 minutes after we boarded the boat, the Mandorri coughed several gray puffs of smoke as its powerful engine spurted to life. An air horn blared as the trawler maneuvered slowly out of the port. Fishermen on other launches looked up from their work, waving as the Mandorri picked up speed and pushed out to sea. Palamós disappeared in a blink, replaced by the jagged cliffs that give this stretch of coast its name: the Costa Brava.

The port of Palamós at dusk.

After two hours on the water, the Mandorri slowed down. Its sonar screen was lit with countless small dots: we were right above a deep-sea canyon dense with prawns. The rumble of the engine was barely heard over the whistling breeze. The sky cleared; there were no other ships in sight.

Miquelito and Gavi Cuellar, 49, stationed themselves behind the winches and grabbed the large steering wheels, guiding the steel cables that slowly released the trawls.

“The net has to fall flat into the sea; if not, it won’t open correctly,” Xavier said as he operated the controls on the deck. The massive green net, fitted with weights and sensors, drifted lazily in the white foam before sinking slowly out of sight.

Translated from the Catalan as the “rough” or “wild” coast, the Costa Brava extends from the French border down to the town of Blanes, just over 35 miles north of Barcelona. Catalonia was once a maritime empire and seafood still constitutes an important part of its local diet. When the Greeks arrived here in the 4th century B.C., they brought with them the art of salting fish, a tradition passed on to the Romans who would eventually build a network of factories on the Iberian Peninsula to produce garum, an expensive paste of fermented fish guts. For millennia, these coastal villages fished for the entirety of Catalonia.

The net took 20 minutes to fall 350 fathoms, or about 637 feet, and would trail behind the boat and above the sea floor for about seven hours. Around 9:30 a.m. the crew was already preparing lunch. “We’ve got to eat early, because we can’t be eating later when something could happen,” José Luis Ramírez, 49, said, as he sliced thick chunks from a baguette and laid them out on a small table covered with newspapers. The men sat down on two narrow benches on either side, ready to eat. A 24-hour news station played on a tiny TV mounted in one corner, the only channel available out here on the water.

Over tin bowls of arroz a la cubana—boiled rice with fried eggs and tomato sauce—and the quiet growl of the engine, the men argued and laughed over their pay, the weekend’s soccer matches and politics. All of them started fishing when they were teenagers and grew up watching their fathers and grandfathers do the same.

The crew — Miquel Jiménez, Gavi Cuellar, and Lluís Ramírez — joke around in the afternoon.

“I can’t wait to retire. Six more years. It’s a difficult job,” said José Luis, who began fishing when he was 13. I asked them how the pay was. “In the summer, it’s good money. I can take home 300 or 500 euros a week,” Gavi said. “But in the winter, you take home very little. Maybe six euros a day.” The fishermen have no fixed salary; instead, they take home a share of the profit from each week’s catch.

“In the 1930s, with the introduction of motors on boats, fishermen discovered large amounts of prawns,” Alfons Garrido, a local historian, told me in an interview at the Palamós Fishing Museum. “They could venture out to deeper waters and their nets went much deeper into the sea.” In a job once dominated by intuition and experience, the introduction of satellite technology and sonar systems made it much easier to find prey.

However, in recent years, overfishing has become a grave concern for local conservationists, as trawl nets that drag across the seafloor have caused large-scale damage to marine habitats. Fishermen like the ones on board Mandorri are worried, too, as the destructive trawl nets resulted in a steady decrease of prawn population until the early 2000s before slowly recuperating in the last decade.

After lunch, the men rotated duties patrolling the ship and helping Miquel upstairs. To pass the time, they smoked cigarettes, read the newspaper and cracked jokes at each others’ expense. Upstairs, Miquel sat quietly, his hands firm on the ship’s wheel, eyes glued to the small dots on the monitors. At around 4 p.m., the deck finally came to life when the crew got ready for the haul. “Let’s see what we’ve got today,” said Miquel, as the rest of the crew slowly pulled the net up.

There were few words and no jokes, only the screech of the seagulls that followed in our wake.

The net flopped onto the deck like a brown, lifeless sea creature. A pile of prawns gleamed red in the afternoon sun, peppered with the shiny silver underbellies of fish, octopuses and small sharks. “It’s very little,” José Luis said. As we headed back toward port at full speed, everyone except Miquel knelt around the catch pile, heads bowed low as they sorted prawns and fish into shallow blue crates. There were few words and no jokes, only the screech of the seagulls that followed in our wake.

The sun was just beginning to set over Palamós when we pulled into dock, 12 hours after setting sail that morning. On the beach, couples lounged lazily and teenagers rollerbladed past the Museum of Fishing.

The museum stands alongside the fish market, where members of a guild-like organization of fishermen called the Confraria inspect freshly caught prawns for quality control each day, ensuring that each crustacean has been kept intact and on ice at a temperature below 41°F. After inspection, the prawns pass through the auction hall on a slow-moving conveyor belt along with crates of squid, octopus and sardines. From here, the seafood is delivered to neighborhood fishmongers across Catalonia, while some will be frozen and sent to restaurants across the world.

Miquel and his crew rearranged the trawler for the next morning and headed home around 9 p.m. Tomorrow they had to come back again at dawn. Their lives are moored in this boat, in the sea—a reminder posted in a sign at the exit of the museum: “Entre tu i un peix, sempre hi ha un pescador”—between you and the fish, there is always the fisherman.

Miquel Fortuny looks on as José Luis Ramírez and Lluís Ramírez sort the prawns.

Miquel said his name was a common one—all the oldest sons in his family were called Miquel. Mandorri, he said, was the nickname of his great-grandfather, who had come to Palamós from the south of Catalonia at the end of the 19th century. Sailors then wore long pieces of cloth, called faixes, around their waists and tucked their linen shirts into these sashes before setting sail. Miquel said his great-grandfather was always a bit nervous and disorganized, and would leave his shirt hanging out like a billowing sail. The other fishermen teased him by calling him en orri—“a disaster.” That nickname eventually became Mandorri.

Despite his appearance, Miquel said his great-grandfather was a man of deep calm and precision, and his success launched the careers of four generations of Fortuny fishermen in Palamós. “You’re always in control over the net that’s hundreds of meters below water,” Miquel said, brushing the palm of his hand as if petting an imaginary cat. “That’s why Xavi can’t be a captain—he’s too hot-tempered,” Miquel said as he smiled at his brother. Xavier grunted.

Xavier joined the Mandorri only four years ago after working for years on their father’s boat, called the Montse. The brothers had a falling-out years earlier over who should take over the Montse when their father retired. Xavier continued working on the crew of the Montse,and came on the Mandorri only after he and Miquel reconciled five years ago.

We sat for lunch—Miquel, Xavier, their families, their parents and I—at the long table covered by plates of lettuce salad with tomatoes and tuna, dry-cured Spanish ham and goat cheese, a casserole of seafood and fish and, of course, a platter of Palamos prawns. I picked one up and gingerly peeled away its hard shell.

“Do you like it?” Xavier asked.

“It tastes like the sea,” I told him.

“It’s boiled with water from the Mediterranean,” Miquel said, “and nothing else.”