Nature restoration to bring species back from the brink

The night before a fateful job interview, Cameron Kerr had a nightmare.

"It was when I was a kid, coming to this zoo," the Taronga Conservation Society Australia chief executive says.

"The things I saw didn't inspire me, they horrified me. It was scar tissue in my brain."

Things have changed a bit since Mr Kerr was a child.

"The job now is to create beautiful environments for them, where people don't worry about the health and welfare of that animal but they're inspired by its beauty," he told AAP.

The transformation of zoos from concrete pits holding animals captive into wildlife sanctuaries trying to save them from extinction is an example of a philosophy other sectors might hope to replicate.

Global delegates discussed becoming "nature positive" at a summit in Sydney during the week with a goal of rejigging economies to value the environment, rather than incentivising profits through its exploitation.

It's something many zoos have already had to face up to but the shift might prove more challenging for industries that negatively impact nature.

Sydney's Taronga is trying to undo some of the damage, channelling its expertise into restoring the environment.

Known as "rewilding", the restoration of habitats and reintroduction of captive-bred threatened species could be a way to address biodiversity loss.

The federal government is also keen to incentivise the practice, with a market for nature repair to open in 2025.

Environment department secretary David Fredericks spruiked the plans to summit delegates.

The market would "bring nature into the economic equation in ways that have never been done before", providing income for landholders while also addressing biodiversity loss, he said.

Landholders could receive tradeable biodiversity certificates for planting diverse native trees and vegetation specific to their region, thereby increasing habitat.

They could also combine those actions with projects to generate carbon credits on the same parcel of land, Mr Fredericks said.

A NSW inquiry on Friday recommended parliament debate plans to amend the state's biodiversity offsets scheme, after being told the existing system lacks transparency and fairness and "simply does not work".

Taronga has extensive expertise in rewilding, Mr Kerr says but much of its work is in arid landscapes, which Australia's interior offers in abundance.

Two bilbies at Taronga's Sydney zoo act as ambassadors for that work in a simulated habitat featuring native birds and red sand from the desert, where it's unlikely they could survive on their own.

More bilbies are being raised at Taronga's central-west NSW facility, where they are protected from feral cats and foxes but can hone their survival skills against native goannas, snakes and birds.

Closer to the east coast, land has been cleared for agriculture, causing further degradation.

Taronga is scouting potential sites with targets to rewild 10,000 hectares.

Government modelling is helping with the search for land likely to offer resilience in a changing climate but still with high biodiversity value.

"That land's much more expensive because it's high-value agricultural land," Mr Kerr said.

But the same characteristics would also make it productive for attracting native species.

"We can do things to encourage that but we are also very confident with the work that we've done with much of our rewilding that we can also seed it," he added.

Critically endangered regent honeyeaters are one example of what happens when a species loses too much habitat and food sources to industry.

A Taronga aviary holds about 15 per cent of the estimated 350 remaining birds, while its breeding programs aim to provide more for rewilding efforts.