Piranhas have a reputation as the most ferocious fish in the world. With razor sharp teeth, they hunt in packs, stripping a body of its flesh in minutes. In this programme, the first of a new series, biologist and extreme angler Jeremy Wade examines whether piranhas deserve the reputation they’ve gained as one of the biggest terrors in the water.
Jeremy travels to Brazil to find out what lurks under the murky waters of the Amazon and attempts to get to the bottom of stories of piranha attacks on humans. Scientists have determined that there are some 60 different species in the piranha sub-family, yet the majority of them are actually vegetarian. It is the flesh eating behaviour of just a couple of species that gives them their reputation.
Before setting off Jeremy visits London Zoo to speak to Brian Zimmerman, an expert on piranhas. Brian explains: “There’s no documented cases of a living human going into the water, and being attacked by a group of piranhas, and being reduced to a skeleton in seconds. But piranha are carnivorous; if they’re hungry, it’s certainly possible that they would attack. But to my knowledge, that’s never happened.”
So are the stories of piranha attacks on humans just myth and imagination? On arrival in Manaus, the city at the heart of the Amazon Jeremy heads to the local fish market. With over 3000 species of fish found in the Amazon River, more than the entire Atlantic Ocean, there’s no shortage of strange looking river monsters here and it’s the home of many a gruesome fisherman’s tale. It’s not long before the locals are regaling Jeremy with stories of piranhas attacking people, but unable to track down any definite details, Jeremy heads to the Amazon to find the fish for himself.
The Amazon River is 4,250 miles long. And piranhas are so common you can catch them almost anywhere. Instead of his usual high tech fishing gear and stealth tactics, Jeremy explains: “I’m just using a bit of bamboo with a short length of line on the end. Just a hook on the end with a piece of wire, so they don’t chomp through the line, a lump of meat. And piranhas are actually attracted by noise and disturbance on the surface.”
Within minutes he’s caught a red bellied piranha which can grow up to a foot long. A protruding jawbone with large chomping muscles means that when the mouth is closed, the triangular teeth from both jaws lock together like a bear trap. They predominantly hunt fish, but they will eat the meat of almost any animal that crosses their path.
Undeterred, Jeremy jumps into the river. When he is not attacked by the piranhas Jeremy says: “If I can swim here then something is missing that is needed to trigger a feeding frenzy.”
He then sets up an experiment in a small swimming pool with 100 red-bellied piranhas which haven’t eaten for days. The fish react to the blood that Jeremy pours into the pool, and attack the piece of meat that he gives them, so he decides to see how they react to something that’s alive, and steps into the pool. Jeremy says: “These piranhas were tearing into a piece of dead meat just a couple of minutes ago, but they’re just not interested in me. So what is it that turns piranhas into vicious, murderous killers?”
Jeremy remembers hearing an account of a bus that crashed into the Amazon in the 1970s where several of the passengers’ bodies were found eaten by piranhas. He unearths a newspaper report from the time and explains, “It reports that on the 14th of November, 1976, the bus was travelling from Manuas to the town of Itacoatiara a journey of about 5 hours. After driving through the night it crashed into a tributary of the Amazon killing 39 passengers. The newspaper also mentions the name of a survivor Dirceu Araújo. I’ve managed to track him down to find out what he can remember from that fateful day.”
Dirceu takes Jeremy to the spot where the accident happened and explains how he escaped from the bus through a window. But when the rescuers arrived a couple of hours later, it was too late for any remaining passengers. He remembers, “There were three children and one baby, actually all from the same family. You know, they were brought up dead. There was one body there that literally been stripped of all the flesh, only the boots were left.”
So although Jeremy has found the bus crash he remembered, because the rescuers arrived so long after the accident, it’s still unclear whether the piranhas attacked their victims alive or if they just fed on the corpses after they had drowned. But Jeremy has details of another case where eight piranha attacks happened on one beach on an artificial lake in just one weekend at the end of the dry season in December 2005.
In a period of seven months swimmers suffered individual piranha bites and unlike the bus crash they were not injured, trapped or bleeding. But Brian Zimmerman has an explanation, “Piranha build their nests in very shallow areas…Somebody wading in shallow water and happens to tread onto the nest of a piranha is definitely going to be susceptible to getting a bite.”
Jeremy then travels to a village built on the river which is known as the Piranha Reserve. He says, “ I’ve come here to find out what life is like living with the constant threat of piranhas. These people are known as Ribeirinhos or River People. Almost everything they need is sourced from or around the Amazon River.”
To test out his theory that piranha are attracted to the thrashing of a distressed animal, Jeremy puts a freshly killed duck into the river on the banks of the village and moves it vigorously. Watching the piranhas attack he says, “ They’ve actually chewed through a huge expanse of feather to get at the meat. And they’ve gone right into the body cavity. The head is just reduced to bone. Both eyes are gone and all this just in a matter of minutes.”
Jeremy meets some of the families who live in the village and deal with the piranhas on a daily basis. Speaking to one of the residents Jeremy explains, “one of his grandsons, who accidentally fell into the piranha-infested water just outside the front of their house, tragically, they couldn’t reach him in time and the piranhas lived up to their fearsome reputation.”
In travelling to this remote part of Brazil, Jeremy found what he was looking for, a first-hand account of piranhas attacking, killing, and eating a human.
“If you have a very specific combination of the right time of year, blood, the struggle of distress, and a trapped or weakened person, you could trigger a piranha feeding frenzy. In a river full of monsters, this is just a natural adaptation to life here in the Amazon. But no matter what, the piranha will continue to evoke fear and horror in each and every one of us.”
Thursday, 12 November 2009, 7:30PM – 8:00PM