A Humpback whale swims in the Pacific Ocean at the Uramba Bahia Malaga natural park in Colombia on July 16, 2013. (Luis Robayo/AFP/Getty Images)

You can find their images on T-shirts, coffee mugs and even bumper stickers. Their immense gray and white bodies have graced many a “save the whales” poster. For more than 40 years, the humpback whale has been an icon of the wildlife conservation movement — majestic, globally beloved and always teetering on the edge of extinction. Until now, that is.

A new report from the federal government says the humpback has actually recovered in leaps and bounds since it was first granted protection under the Endangered Species Act (ESA) in the 1970s. And now, the government wants to give everybody’s favorite whale a fresh start.

On Monday, the National Oceanic and Atmospheric Administration (NOAA) released a proposal that would divide the whale into 14 distinct population segments, instead of one large population, and would remove federal protection from 10 of the segments. Of the remaining four population segments, two would keep their endangered status and two would be relisted as threatened.

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This is a major shift for the humpbacks, which have spent the last few decades soldiering back from the brink of extinction. The Wildlife Conservation Society estimates that, at their lowest point, some humpback populations sank to just 2 percent of their original size, suffering the dramatic effects of commercial hunting.

Since then, a ban on commercial whaling and a many-pronged conservation effort, bolstered by national and international initiatives such as the Marine Mammal Protection Act and the efforts of the International Whaling Commission, have helped the whales build their numbers back up. In many ways, the humpback has been a “keystone to conservation efforts around the world,” says Howard Rosenbaum, director of the Wildlife Conservation Society’s Ocean Giants program.

Additionally, the global attention the humpback has received over the years has made it one of the world’s best known and most charismatic species. Their distinctive display behavior — the jumps and breaches that delight whale watchers — and their breathtaking “singing” have made them favorites of wildlife enthusiasts around the world.

So it’s no surprise that NOAA’s recent proposal drew media attention from around the world. Citing population rebounds and continued population growth, the agency hailed the decision as an “ESA success story,” said Eileen Sobeck, assistant administrator for fisheries at NOAA, in a statement. “As we learn more about the species — and realize the populations are largely independent of each other — managing them separately allows us to focus protection on the animals that need it the most.”

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It’s just a proposal for now, and the agency has opened a 90-day comment period for citizens to voice their thoughts before it makes a final decision. But even if the proposal becomes a rule, does that mean we can finally stop worrying about the humpback whale?

Not so fast, experts say.

Rosenbaum, of the Wildlife Conservation Society, cautions that the humpback’s journey isn’t over yet. Under the ESA’s specific listing criteria, 10 of the newly designated humpback populations are no longer threatened by extinction, which is the requirement for “endangered” status. But while the proposal should be taken as a good sign, Rosenbaum says, it doesn’t mean that the whales have made it all the way back to the numbers they had before whaling became a problem. Some populations still have a long way to go before they reach those levels again.

In fact, some conservationists say it’s too soon to propose delisting the whales at all, citing a range of risks that could still threaten the species in the future.

“We’re not embracing this as a great next step,” says Regina Asmutis-Silvia, executive director of Whale and Dolphin Conservation–North America. In addition to ocean noise, pollution, habitat degradation and other risk factors, she says, the two biggest threats to humpback whales today are becoming tangled in nets and getting hit by boats, concerns shared by other conservationists.

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Another complicating factor is the looming threat of climate change, which many scientists expect will become an increasing problem for marine organisms in the future. Miyoko Sakashita, oceans director at the Center for Biological Diversity, says the biggest concern about climate change is how it will affect the whales’ food sources. Some studies suggest that changing ocean temperatures and currents could drive the small fish and other organisms that humpbacks and other whales feed on to different regions of the ocean, meaning whales might have to change their migration patterns to keep up.

Sakashita adds that ocean acidification, which happens when the ocean absorbs large amounts of carbon dioxide from the atmosphere, is another threat to some of the organisms humpback whales eat, such as plankton. These tiny marine creatures protect themselves by building shells out of calcium carbonate. But as the ocean grows more acidic, plankton have trouble pulling the right chemicals out of the ocean to make their shells. “It’s not clear if the abundance of plankton will be the same [in the future],” Sakashita says.

These are all issues the federal government considered in its proposal. The report examined a wide range of potential threats to the species, including coastal development, environmental contaminants, disease, man-made ocean noise, net entanglement and vessel strikes. For some of these factors, NOAA acknowledged that there was not enough data to say for sure what their future effects might be. But, at least for the 10 populations recommended for delisting, the agency determined that the combined potential risks were not an extinction threat.

Climate change wasn’t left out of the picture, either. In fact, NOAA Fisheries examines the potential effects of climate change in any ESA-related decision, a NOAA press officer confirmed, including listing, delisting and reclassifying species.

Acknowledging that climate change “has received considerable attention in recent years,” the authors of the proposal examined the threat it poses to each of the 14 proposed humpback populations. For the 10 they recommend delisting, they concluded that the climate threat was either unknown or not severe enough, in combination with the other future challenges humpbacks might face, to warrant keeping their ESA protection. They also cited data to suggest that humpbacks are likely to redistribute, or shift their ranges, in response to climate-related pressures.

Further reviews are in store before any final decisions are made about the species’ listing status. In the meantime, Rosenbaum says it’s important to make sure the NOAA proposal doesn’t lead to misunderstandings about the humpbacks’ actual recovery status, which will require continued effort from conservationists.

“I think it’s a positive sign that these populations are recovering, and I think it shows when the acts are enacted and enforced and monitored that they can be effective,” he says. “There’s progress, but there’s more work to do to ensure their full recovery.”

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