Conservation efforts have brought back an endangered species of fish in the Amazon

SARAH MCCAMMON, HOST:

Now a big fish story - seriously. In the Amazon jungle, there is a species of giant freshwater fish. The pirarucu is prized for its meat and targeted by illegal fishermen, and it had become an endangered species. But as John Otis reports, this lunker is making a comeback.

(SOUNDBITE OF WATER SWOOSHING)

JOHN OTIS, BYLINE: Here along the Amazon River in northern Brazil, you don't need a fish finder to locate the pirarucu. These are air-breathing fish that must rise to the surface every 15 minutes or so to gulp oxygen.

We've got nine fishing boats here. They've seen several pirarucu jump out of the water. So they're going to spread the nets here.

Quickly paddling their boats, these fishermen lay down their nets in a wide circle to trap the fish.

Looks like they've caught one. Yep, it's in the net.

But the battle is not yet over. Pirarucu grow nearly 10 feet long and weigh up to 450 pounds. Their violent thrashing could injure anyone trying to land them.

UNIDENTIFIED FISHERMAN #1: (Speaking Portuguese).

OTIS: So the fishermen resort to what seems like "Flintstones" technology. They use wooden clubs to knock the fish senseless.

(SOUNDBITE OF FISH CLUB LANDING)

OTIS: This one weighs about 170 pounds. And after some struggle, they pull it into the boat. It looks prehistoric with a gaping mouth, reddish scales and a rudimentary rounded tail like an eel. The fishermen are exhausted, but pleased.

AILTON BRUNO: (Speaking Portuguese).

OTIS: "Today is a good day. We've already caught eight fish," says their boat captain, Ailton Bruno. Catching them used to be a lot harder. In the 1990s, overfishing caused the pirarucu to nearly vanish from some parts of the Amazon, says Edivan Ferreira, who lives in the riverside village of Boa Vista do Calafati.

EDIVAN FERREIRA: (Speaking Portuguese).

OTIS: He recalls his father fishing for five days and coming home with a single pirarucu. But now, he says, the fish are flourishing. That's because Boa Vista sits inside a nature reserve called Mamiraua, where communities practice sustainable fishing.

UNIDENTIFIED FISHERMAN #2: (Speaking Portuguese).

OTIS: Here's how it works. First, fishermen count the number of pirarucu in nearby lakes and rivers by watching them leap out of the water. After reporting these numbers to environmental officials, they're allowed to catch 30% during a fishing season that lasts just a couple of weeks. The fish are tagged so buyers will know they were caught legally.

ANA CLAUDIA TORRES: (Speaking Portuguese).

OTIS: The result, says Ana Claudia Torres, who runs the sustainable fishing program in the reserve, is that the pirarucu population has recovered with a tenfold increase along some parts of the Amazon. However, outside of nature reserves, illegal fishing remains a big problem, one that is often financed by drug traffickers.

TORRES: (Speaking Portuguese).

OTIS: Torres says smugglers often hide cocaine aboard fishing boats and use the fishing business to launder their drug profits. The issue made headlines in June. That's when British journalist Dom Phillips and Brazilian environmentalist Bruno Pereira, who were investigating illegal fishing in the Amazon, were shot dead by a poacher.

TORRES: (Speaking Portuguese).

OTIS: Torres says the killings shocked many Brazilian environmentalists who fear they could be next. Still, she's determined to press ahead because the sustainable fishing program is working.

UNIDENTIFIED FISHERMAN #3: (Speaking Portuguese).

(SOUNDBITE OF SPLASH)

OTIS: Each pirarucu caught in the Mamiraua reserve sells for about $100. That's a huge boost for riverside communities that get by during the rest of the year on subsistence farming. Still, they have to move fast.

BRUNO: (Speaking Portuguese).

OTIS: Bruno, our boat captain, says they need to get the fish out of the tropical heat and ready for shipment within a few hours. Otherwise, the meat will start to spoil.

(SOUNDBITE OF BRUSHES SCRUBBING)

OTIS: At this one-room processing plant on the river, workers gut the pirarucus and wash their insides with scrub brushes. Then the fish are put aboard cargo boats.

Now the fish are down in the storage hold of the boat, and the workers are throwing buckets of ice over the fish to keep them cold for the journey down river so they can get to market.

Their final destination is the Amazonian capital of Manaus, where the fish are a hot item. Indeed, nearly all of the pirarucu end up on the plates of diners in Brazilian restaurants. For NPR News, I'm John Otis in the Amazon River, Brazil. Transcript provided by NPR, Copyright NPR.