The Obama administration on Tuesday announced a deal with environmentalists to work through a backlog of more than 250 imperiled animals and plants and decide which merit greater protections.
Most would likely be proposed for threatened or endangered status if a federal judge approves the agreement, Interior Department officials said. The species to be reviewed range from the greater sage grouse and Canada lynx, to 110 plants and 38 kinds of mollusks.
That could lay the groundwork for a spate of future conflicts over industrial development, water management and residential expansion wherever humans are encroaching into the natural world.
Conservation groups and government agencies in some cases already are working to prevent such disputes, hoping to avoid a repeat of the bitter fights that emerged over protections for the northern spotted owl, gray wolf and snail darter.
Some of the plants and animals in the announcement were first proposed for protection soon after the passage of the Endangered Species Act in 1973. Instead, they languished for decades on a list of "candidate species" that the government could not afford to help.
Final decisions would be due by September 2016. It would settle pending litigation between the Interior Department and Denver-based WildEarth Guardians.
WildEarth is among a handful of groups that have filed hundreds of legal actions against the agency, hoping to force it to make it extend protections to candidate species. Those comprise a long list of fish, birds, mammals, plants and even snails that scientists already have determined need greater protections to avoid extinction.
Deputy Interior Secretary David Hayes said the backlog has been made worse by lawsuits that have distracted the Fish and Wildlife Service from needed scientific reviews and restoration work.
"This plan will enable the endangered species program to function as it was originally intended," Hayes said. "Priorities are being set by plaintiffs in courts, instead of by wildlife professionals."
But approval of the settlement could be complicated by opposition from another group involved in multiple lawsuits over endangered species, the Center for Biological Diversity.
The Tucson, Ariz., group is a plaintiff in some of the cases before U.S. District Judge Emmet Sullivan covered by Tuesday's settlement. Director Kieran Suckling said he was approached by the Interior Department but refused to sign the deal because the government omitted key species that could be harmed by climate change.
Suckling said two candidate species left out of the deal _ the wolverine and Pacific walrus _ merit protections that could potentially affect tens of millions of acres in the Rocky Mountains and the Arctic.
"They have massive implications for combating global warming and the administration is trying to avoid that at all costs," Suckling said.
Interior officials also said they plan to make initial findings on an additional 600 species for which groups have filed petitions seeking greater protections.
J.B. Ruhl, a property law professor and endangered species expert from Florida State University, said he expects the aquatic species covered in the announcement to be the source of the most controversy in the future. Any new protections for those fish and mollusks would come as competition for water resources increases nationwide, he said.
"More and more we're seeing aquatic species driving water-management decisions, not just in the West, but I think that's going to creep over to the East as well," Ruhl said.
Another environmental law expert said that four decades of experience had shown the economic disruptions caused by federal protections are usually local _ and worth the cost of preserving biological diversity.
"What you're always doing is balancing the cost of a single project _ an oil and gas lease, a golf course _ against the very existence of a species forever," said Fred Cheever of the University of Denver. "In almost every case, you have to give the species the benefit of the doubt."
Interior officials pointed to conservation work already initiated for one candidate species, greater sage grouse, as an example of efforts under way to avoid contentious restrictions. As oil and gas development expands into the ground-dwelling bird's habitat in Colorado, Montana, Wyoming and other Western states, agencies are working with landowners to preserve core areas where the birds could recover once the energy boom has passed.
Environmental groups had previously charged the Obama administration with doing little to improve on what they consider a dismal record on endangered species under President George W. Bush.
The Obama administration has listed 59 species as endangered _ a rate of about 30 a year. That's up significantly from the Bush years, when the average was eight per year, but far behind the 65 species per year under the Clinton administration.
Some conservationists said Tuesday's proposal redeems the administration.
"Today's announcement greatly changes the legacy and the track record that Obama is going to have,"" said Leda Huta with the Washington, D.C.-based Endangered Species Coalition.
As part of the deal, WildEarth Guardians said it will limit the number of petitions it files to ten a year.
The group's wildlife program director, Nicole Rosmarino, said many of those petitions were bound to end up on the candidate species list under the status quo.
"We and the government agree that the day has come to address the future of the endangered species candidates. This will be an important step toward protecting the rich biodiversity in the U.S. and stemming the extinction crisis," Rosmarino said.