WASHINGTON: Lots of people find a home on the National Geographic Channel, from tuna fishermen to Mormons with more than one wife and “preppers” stocking up their bunkers for the end of the world.

The popular cable and satellite TV channel traces its heritage to the 125-year-old magazine of the National Geographic Society, one of the world's biggest non-profit scientific and educational organizations.

A scholarly journal at the outset, the magazine with its signature yellow-border cover now claims a global readership of 60 million with its domestic English and 36 foreign-language editions.

To the chagrin of purists, however, the National Geographic Channel – majority owned by Rupert Murdoch's News Corporation – has a distinctly more popularist flavor.

One of its most-watched series is “Doomsday Preppers,” which introduced such colorful survivalists as Tom Perez, who's so involved in preparing for an imminent terrorist attack that he hasn't worked for 12 years.

“Wicked Tuna” hinges on the rivalry between rival fishing crews in Gloucester, Massachusetts whose livelihoods depend on catching tuna the hard way, with rod and reel. Its third season is in production.

Then there's “Polygamy, USA” starring a breakaway Mormon sect that stays true to plural marriage; “Ultimate Survival: Alaska,” a deep-freeze test of wilderness wits; and many other so-called “docu-reality” series.

“Genuinely, it's contemporary anthropology, and these are really significant subcultures,” said Hamish Mykura, the National Geographic Channel's head of international content, based in London.

“There will always be some people who think that National Geographic should just be making programs about elephants and glaciers and Papua New Guinea,” he told AFP. “But if you are going to make a TV channel that people want to watch and that is interesting and entertaining, your challenge is something much more important and significant than that.” The bottom line is characters, added Mykura, a veteran of Britain's BBC and Channel 4 television networks.

“In some ways it's more interesting to tell the story of a person through their own experience and through their own words than to have a commentator you don't see reading a narration and giving an opinion from behind the camera.” For those loyal to old-school National Geographic values, some of whom may remember its first network TV special “Americans on Everest” in 1965, there's gnawing sense of heresy. It was those values, for instance, that saw the magazine a century ago publish the details of Hiram Bingham's discovery of the Inca ruins of Machu Picchu in Peru.

“The National Geographic Magazine has always worked hard to stick to the facts,” said Alan Mairson, a former staff writer at the magazine whose Society Matters blog critiques what it calls the society's “broken business model.” “The channel is focused on entertainment,” he said. “The magazine is focused on education while it simultaneously tries to deliver riveting stories.

The two approaches are fundamentally different.” Wildlife documentary filmmaker Michael Parfit, a former contributor to the magazine, said the credibility of the National Geographic Society has been undermined by the Channel's programming.

“A few (programs) seem relatively honest, so they approach documentary quality,” he said. “Many are simply semi-scripted entertainment with main characters who play themselves when given fictional situations.” “The shows I find most offensive are presented as documentaries or character-driven series about specific subjects that have been fully debunked by science,” he said, citing “Chasing UFOs” as an example. Mairson suspects the Murdoch factor is at play.

“What does Rupert Murdoch gain from operating under the National Geographic name? Trust. A sense of authenticity. A comfort level for viewers that was evidently lacking at the Fox Reality Channel,” which Fox took off the air in 2010, he said.

For Dave Carraro, one of the stars of “Wicked Tuna,” the National Geographic Channel has done a good job in showing viewers “the highs and the lows” of his risky life on the open seas.

His colleague Dave Marciano also appreciates the extra income that comes with appearing on reality TV -- a cushion for the time spent waiting for the fish to bite. “They don't show the 75 per cent of the time when we sit up there, picking our noses,” he said. “You've got to invest a lot of time. That's the biggest investment we make, waiting and waiting and waiting.”