Dallas, Texas (CNN) It's a place where serious big game hunters hang out and network -- kind of a supermarket for hunting enthusiasts.

Tens of thousands of them have come from all over the world to the annual Dallas Safari Club Convention & Sporting Expo.

Everywhere you look in this sprawling 800,000-square-foot convention you see weapons, gear and just about every type of hunting paraphernalia available. There are also lots of animals -- none of them alive. Rhinos, lions, antelopes and various types of big game animals that have all been stuffed by taxidermists to be trophies in someone's home or office.

Want to book the hunting adventure of your dreams?

If you pony up enough cash, you'll find yourself heading to remote parts of North America, Africa, China or Russia -- places many people can only dream about -- for the chance to track and kill some of the world's most magnificent and endangered beasts.

The annual convention takes place during a critical time for big-game hunting. Activists are fighting hard to stop it -- while hunters are trying to save it. And the debate is centered around a concept that aims to create a model for sustainable hunting.

The convention includes lots of animals -- none of them alive.

Many of these hunters here pass the time trading stories about how they've bagged some of nature's most exotic animals -- following a tradition made famous by writers such as Ernest Hemingway.

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Avid hunter Corey Knowlton attends the convention every year and is here as usual -- surrounded by the expo's more than 1,850 exhibits. In 2014, this was where he successfully bid $350,000 at an auction to hunt and kill a black rhino in Namibia

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"I care about all of wildlife in wild places, and I want it to be around for our future generations," Knowlton told CNN, getting slightly emotional. "I believe this is the best model that exists for it, if you like or you don't like it."

The model he is referring to is "conservation," terminology that is part of The Dallas Safari Club's mission statement, and a debate that Knowlton knows well after his rhino hunt.

And even though the animal is considered "critically endangered" by wildlife organizations around the world, Knowlton is steadfast in his belief that sustainable hunting like this is the key to help save the black rhino species.

"It's about a value on wildlife, and the proof that it works is the fact that we are sitting here in this building, and all these people are marketing and supporting wildlife, and so there is a value on it beyond its value of meat," Knowlton said.

Namibia

There are only around 5,000 black rhinos left on the planet, according to the World Wildlife Fund and Namibian government officials say their nation has the second-highest population anywhere. Namibia earmarks a small quota of the animals to be hunted annually. The country describes the income generated by hunts like Knowlton's as "critical" for supplying the infrastructure used to help save the wildlife from extinction.

"We have taken a conscious decision to sustainably harvest some of the older wildlife, some of the post mature bulls that are basically fighting with the young ones, sometimes killing the young ones or females," Johnson Ndokosho, deputy director of Wildlife and National Parks with Namibia's Ministry of Environment and Tourism told CNN from the convention floor.

Photos: Namibia's poachers turned gamekeepers Keeping big game in their sights – Much of Namibia's wildlife on communal land was critically endangered until the 1980s, but a radical rethink to make poachers 'game guards' reversed the fortunes of many community members and has led to a steady increase in animal numbers. Hide Caption 1 of 6 Photos: Namibia's poachers turned gamekeepers Staying out of the pot – For many Namibians living on communal lands during the period apartheid-era South Africa ruled Namibia, poaching springbok and zebra was the only way a family could stay fed, according to John Kasaona. Hide Caption 2 of 6 Photos: Namibia's poachers turned gamekeepers Expanding an idea – The idea to make the community stewards of their land came from the Integrated Rural Development and Nature Conservation (IRDNC) in 1983. The idea was adopted more widely after independence with more "community conservancies" created after1990. Hide Caption 3 of 6 Photos: Namibia's poachers turned gamekeepers Ownership as incentive – "If people feel they really own a resource, if they feel they have responsibility for it, they're going to be accountable, and they're going to look after it," says Margaret Jacobsohn of the Integrated Rural Development and Nature Conservation. Hide Caption 4 of 6 Photos: Namibia's poachers turned gamekeepers Wildlife safaris – Working closely with local communities is alsothe best way to make a success of tourism ideas like the Damaraland Camp eco-resort. Hide Caption 5 of 6 Photos: Namibia's poachers turned gamekeepers A sizeable effect – When the government conservancy system started in 1996, there were four conservancies. Today there are 74 across Namibia, earning around $4million a year. Most of the money is from joint venture tourism, with trophy hunting following in at a distant second. Hide Caption 6 of 6

He said the money goes directly to fund conservation activities, water for wildlife, anti-poaching operations, equipment for the community and research.

Ndokosho said the funds protect the wildlife and help improve the livelihood of the Namibian people. He said since 2015, levels of rhino poaching in his country have declined.

Frans Kamenye, the fund manager for Namibia's Game Products Trust Fund, said the $350,000 raised from Knowlton's 2015 hunt was used to buy ten Land Cruisers, an air patrol boat, four amphibian eight-wheel vehicles, and gasoline -- all key resources that are used by anti-poaching task forces.

"In Namibia, hunting is something that we need. Otherwise, we have seen many countries where there is no hunting, it's failing because there are no resources," Kamenye told CNN.

A 'real threat to the survival of animals'

Of course, the global debate is filled with passion on both sides of the issue, and critics of the hunting-as-conservation approach have different perspectives.

They would like to see funds raised to protect species without any killing, and stress that widespread education to show that animal horns have no real medicinal value would help solve and curtail the poaching demand.

Away from the sea of taxidermy scattered across the convention floor, Prashant Khetan, Chief Executive Officer and General Counsel at Born Free USA, an animal advocacy organization, insists that hunting as a conservation model has no merit. Instead, he views it as a "sport" and "horror show." In fact Khetan said it's a "real threat to the survival of the animals."

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Trophy hunting as a conservation strategy "is just a myth," Khetan said. "I think it's a mere contradiction to even think about killing animals is in some way going to help the survival of a species."

Any benefits of conservation programs Khetan said, are "grossly exaggerated."

Because of rampant corruption and "lack of oversight" only a small percentage of the money generated from many hunts actually ends up where it is supposed to, Khetan said, benefiting an elite few -- like governments and private companies -- and not the animals or the general public.

'A proven success'

Back amid the exhibition space full of enthusiasts at the Kay Bailey Hutchison Convention Center in downtown Dallas, conservation organizations from across the globe are represented.

Before joining the Dallas Safari Club as executive director last September, biologist Corey Mason says he spent the last sixteen years with the Texas Fishing and Game Agency working with conservation agencies and organizations all over North America.

He says that the restoration of many species on the continent shows that "the conservation through hunting model is a proven success."

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He has no doubt that well-regulated hunting programs based on science are sustainable -- as long as specific quotas are developed and followed. The animals that are taken, he said, represent a very small percentage of the population, and in most cases they are older-aged males.

Mason said the money raised through "scientific" conservation is used to protect the habitat where the animals live and to combat poaching.

Knowlton acknowledges that he has a lot of respect for outspoken critics of conservation hunting. But he also questions their "understanding of reality."

"Every single one of (these animals) is going to die," Knowlton said. "But if you have the power to put a value on it, and supply those communities that are very poor with money ... I believe it's a very good symbiotic relationship."