The environment minister, Greg Hunt, has set out his vision to reverse the precipitous decline in the number of Australian species, pledging to end the loss of native mammal species by 2020.

Hunt admitted Australia has a legacy of “clear and significant failures” in protecting its wildlife, citing the fact that the country has the worst rate of mammal extinctions in the world, with 29 species perishing in the past 200 years.

“I have set a goal of ending the loss of mammal species by 2020,” Hunt said in a speech in Melbourne on Wednesday.

“What’s more, I want to see improvements in at least 20 of those species between now and then. Our flora and fauna are part of what makes us Australian. I don’t want the extinction of species such as the numbat, the quokka, the bilby, on our collective consciences.”

To achieve that goal the government will wage war on the feral cat population, which has been cited by scientists as a leading threat to Australian native species. There are about 20m feral cats in Australia, which are understood to slaughter an astonishing 75m birds and ground-dwelling mammals every day.

Hunt said a “potential game-changer”, a new bait called Curiosity, would be developed to suppress feral cat numbers in key areas, with the animals targeted for complete eradication on Christmas Island.

Hunt promised further federal government intervention to protect species in Kakadu, Norfolk Island and Raine Island in the Great Barrier Reef, known for its sea turtle population.

Another $3.3m will be spent protecting the Tasmanian devil, while Hunt indicated a new initiative to help the endangered Leadbeater’s possum, which is Victoria’s faunal emblem but is under severe threat following the Black Saturday fires and, environmentalists say, irresponsible logging of habitat.

The $525m Green Army, a Coalition creation that deploys groups of young people to revegetate areas and tackle weeds, was cited by Hunt as an avenue for protecting threatened species, although the first round of Green Army projects contains few specific references to combating feral cats and other pests.

Hunt said legislation had “clearly failed” to arrest the decline in threatened species, pointing out that the national list of endangered mammals, birds, fish and reptiles contained 1,749 species and “grows year by year”.

“I know too well that legislation alone is not the solution,” he said. “It can provide a framework and a guide, but too often we become complacent and expect the laws to provide the solution. As our track record on the environment shows, that has provided only limited success.

“Good policy and change is driven by the community. The environment is no different. My aim as minister is to inspire people to join me on this journey, to refocus the way we manage our environment and to help the community engage at their local level.

“It is only then that we will see a real difference and it is one that no legislator will ever achieve by law alone.”

Hunt defended the government’s plan to devolve environmental approvals to the states, stating that the move has already resulted in Queensland, New South Wales and South Australia adopting higher environmental standards to meet federal criteria before the handover, as well as providing millions of dollars in potential economic benefits.

The environment minister stressed that he had addressed concerns raised by the auditor general in June that the environment department was understaffed and “passive” when enforcing regulations. The number of compliance staff had been tripled, Hunt said.

Hunt admitted the Great Barrier Reef was under pressure but said he was proud that a plan to dump dredged spoil into the reef’s marine park had now been averted, after he initially approved it late last year. “If I achieve nothing else, I will be satisfied with that,” he said.

Jess Abrahams, a healthy ecosystems campaigner at the Australian Conservation Foundation, said he was encouraged by much of Hunt’s plan.

“The ambition of protecting mammals by 2020 is great and the ambitions of the threatened species commissioner to keep all endangered species in the wild for the next 100 years is fantastic,” he said. “It was also good that he acknowledged the legacy of past mistakes.”

But Abrahams said the government needed to do more to protect the habitat of threatened species, saying the recent approval of the huge Carmichael mine in Queensland would imperil the home of the endangered black-throated finch.

“The minister talks about the mine as if it’s a barren landscape but he won’t acknowledge it’s the home of a threatened species,” he said. “If he can’t use his power to protect threatened species, who can?

“I don’t see the government doing what’s required to deliver. The cat baiting is great, but species will continue to decline if the government allows their habitat to be destroyed and dollars aren’t provided to implement the threatened species plans.”