Ecotourism has become mainstream, with properties doing more than simply asking guests to reuse bath towels.

The trend doesn't look set to wane anytime soon, with ecotourism operators reaping financial rewards as travellers expect more and opt to stay at properties embracing green initiatives.

Ecotourism Australia chief executive Rod Hillman says what was considered special and unique 10-15 years ago is now standard hotel business practice.

Initiatives go beyond reusing towels too, with hotels installing efficient energy systems and better managing waste water.

"The whole industry has taken a significant shift along this spectrum," says Hillman, and the business benefits are impressive.

The annual revenue for eco-certified operators in Australia recently topped $1 billion, he says.

Operators are certified by organisations such as the not-for-profit Ecotourism Australia, which aims to broaden the use of ecotourism principles across the industry.

Although there is a cost to certification, it's based on a company's turnover, meaning that smaller business aren't disadvantaged.

Ecotourism Australia falls under the T-QUAL Accreditation umbrella, which encompasses more than 11,000 Australian tourism operators. If a tourism operator has the T-QUAL Tick then it meets the federal government's quality standards. This makes it easier for people to make informed holiday choices.

"What it means is that as a client is you can go to these places and you know that these people are doing the right thing," says Hillman.

Joost Heymeijer, general manager of Emirates Wolgan Valley Resort and Spa in NSW, says the trend towards more environmentally-sustainable practices has been growing rapidly over the past decade.

"Travellers are now much more sensitive to environmental issues – especially their own impact on the locations and communities they visit," Heymeijer says.

Hillman agrees, saying holiday-makers want to see that the ethos they live by is replicated and acknowledged by the people they're going to stay with.

Ecotourism started to become important during the International Year of Ecotourism in 2002, when industry representatives met with state and federal governments developing nature-based tourism strategies.

The Cairns conference, says Hillman, gave incentive for many in the industry to embrace environmental programs.

"A lot of the industry just went 'this actually makes a lot of sense, this is better for my business'.

"And all the research is showing that people want a quality product in a natural setting, and to have meaningful experiences and really connect with whatever's happening in that area."

Although hotel developers often come under fire for building in areas that are pristine and devoid of tourists, there are plenty of properties in Australia that are proving it can be done sustainably.

Examples include Lady Elliot Island Eco Resort and Heron Island both in the southern Great Barrier Reef, as well as the Berkeley River Lodge and Eco Beach in WA.

"It is gratifying to see more and more industry colleagues becoming more socially and environmentally responsible and we commend them for their positive contributions," says Heymeijer.

"About 10 years ago, when the concept of a luxury conservation-based resort for Australia was being discussed, there was a huge gap in the market for such an offering," says Heymeijer, referring to Wolgan Valley.

"It has been great to see the emergence of other properties in Australia, such as Qualia, Southern Ocean Lodge and Saffire Freycinet, enjoying success by showcasing Australia's breathtaking and fragile environment to high-end travellers."

Wolgan Valley Resort and Spa sits on a 1600-hectare conservation and wildlife reserve and promotes itself as the first carbon-neutral resort in the world. Its green initiatives include the planting of more than 200,000 native trees, creating a kitchen garden and sourcing seasonal and locally-grown organic produce.

But, as is the case with the food industry, the tourism sector also suffers from "green washing" – where companies claim to be sustainable but not necessarily are.

Hillman says travellers can avoid these places by looking for certified providers.