Isle Royale's decimated wolf population will get a lifesaving infusion of 20 to 30 new wolves over the next three years under a National Park Service plan published today in the Federal Register.

The Park Service published its final environmental impact statement after studying the potential of wolf reintroduction for two years and deciding on bringing in new wolves over other options, including doing nothing.

Park Service officials now must wait for 30 days before a “record of decision” is published and details of the relocation plan can be released, said Liz Valencia, chief of interpretation and cultural resources for Isle Royale National Park.

The final environmental impact statement comes more than a year after Isle Royale National Park officials reached the conclusion that the wolf transplant was the best and only option to keep a viable predator population on the island. But it took more than 15 months for the efforts of the environmental impact statement to clear the agency’s hierarchy.

As of January there were only two wolves remaining on the island as the wolf population has been slowly declining due to inbreeding and genetic deformities.

Scientists with Michigan Technological University, who have been studying the island's wolf and moose populations for 59 years, have said for years that the wolves need new blood or they face extinction. The last two wolves are father and daughter and when they have mated their pups have not survived.

Some people had suggested that the Park Service stay out of the situation and let the island's wolves run their course, saying the definition of federal wilderness is an area not impacted by human action. But others say the problems wolves face - including vastly diminished Lake Superior ice cover due to climate change, which makes it less likely for new wolves to come to the island - show humans already are having an impact.

The 45-mile-long, 143,000-acre island is located about 15 miles off Minnesota's North Shore.

Wolves are relatively new to the island, having crossed the ice in the 1940s. Their numbers reached a high of 50 in 1980, and 24 wolves roamed the island as recently as 2009. But no new wolves have crossed ice to the island in many years.

Moose came to the island much earlier in the 1900s, peaking at 2,445 in 1995 and hitting bottom at just 385 in 2007. In their annual survey last winter scientists estimated the moose herd had grown to 1,600 on the island.

Results of this winter’s survey, due in coming weeks, are expected to show 2,000 or more moose now on the island. Without more wolves, scientists say, the moose will continue to increase and cause environmental damage across the island and will begin to starve to death.

The Humane Society of the U.S., an animal welfare group, was first to weigh-in Friday supporting the Park Service decision.

“With the loss of Isle Royale’s ice bridges due to climate change, wolves could not reach the island. This spelled disaster not only for the park’s environmental health, but doomed its overabundant moose population to slow, cruel starvation,” said Nicole Paquette, vice president of wildlife at The Humane Society of the United States. “The two wolves left on the island are too inbred to successfully reproduce; it’s been heartbreaking to witness the harm that lack of genetic diversity has caused on Isle Royale.”

In the draft environmental study the Park Service says it will look to capture Great Lakes wolves that are known to feed on moose as one of their prey sources, are in good health with no apparent injuries and have the appropriate genetic diversity to sustain a viable population on the island.

Capture and relocation efforts would take place between late fall and late winter. Relocated wolves will be fitted with radio or GPS collars so they can be tracked.

Wolves may be supplemented as needed up to the third year after initial introduction. After the third year, should an unforeseen event occur that impacts the wolf population, such as a mass die-off or introduction of disease, additional wolves may be supplemented for an additional two years. No additional wolves would be brought to the island after five years from first relocation.