Image copyright AP

Elephants, sharks, and toads have one thing in common. All of them have benefited, in some way, from the presidency of Barack Obama.

One of the lesser known legacies of the US president is his record as a conservationist.

During his eight years in office, he has placed 548 million acres of habitat under protection. This spans Arctic tundra, mountain woodland, and coral reefs with as much biodiversity as rainforests. The outgoing president created the two largest marine reserves on earth and the world's second largest desert reserve.

Collectively, this array of land and sea encompass an area nine times the size of the United Kingdom.

Mr Obama has protected more natural habitat than any president in American history, exceeding the 290 million acres by the founder of US National Parks, President Theodore Roosevelt.

In all, Mr Obama has added 22 new parks to the US National Park system, far exceeding the six created by his predecessor, George W Bush.

Image copyright AP Image caption The Obama administration has seized thousands of illegal wildlife products as part of its global crackdown on the trade, issuing $12.5m (£10.1m) in fines in 2015

Some of his conservation measures have faced resistance.

In January 2015, the president was scolded by a host of Republicans for expanding the Arctic National Wildlife Refuge by 12 million acres, against the wishes of the oil and gas industry who were blocked from drilling in the expanded reserve.

Environmentalists have also found fault with his policies.

"I would give Obama's wildlife legacy a B minus," says Kieran Suckling, executive director of the Center for Biological Diversity.

"He has a mixed record. He has put a lot into climate change and land preservation, but never prioritised wildlife."

Critics point to his administration's initial delisting of the grey wolf as an endangered species, lacklustre polar bear protection, and smaller projects, like an under-funded bid to restore pollinating bee and butterfly populations in the US.

Image copyright Getty Images Image caption Many of Obama's conservation efforts have focused on Hawaii, the president's place of birth

But even the most demanding of environmental groups admit they have been broadly pleased with his work.

"Of course, we always want more," says John Hocevar, Oceans Campaign Director for Green Peace.

"But on protected areas [he] has done reasonably well. It is really important the US leads on marine conservation issues, and he did this at various essential moments."

Among the more notable international moves is the creation of the Ross Sea marine reserve in Antarctica, a habitat twice the size of Texas - home to seals, penguins, whales and giant swarms of krill.

Creating the reserve took years of negotiation with Russia and China.

"If our ocean ecosystems are to survive," says Hocevar, who is also a marine biologist. "We need more reserves like this."

Image copyright Getty Images Image caption The Ross Sea, a protected area formed by Obama in co-ordination with Russia and China, is the largest marine reserve on earth

The Obama administration has also put resources into the protection of individual species, including backing a law to make shark fishing more sustainable, and naming the American bison as the country's "national mammal" in an effort to raise the profile of the endangered and historic animal.

One species, the Tanzanian Kihansi spray toad, was rescued from extinction by a coalition of conservation groups and the US interior department.

A lot of the movement on protecting endangered species has been "bipartisan", says John Calvelli, vice-president of public affairs for the Wildlife Conservation Society.

"Republicans have led the way, too."

The US Fish and Wildlife Service has crushed and burnt more than 6,000 tonnes of elephant ivory and $1m (£800,000) worth of rhino horn on American soil during Obama's presidency, building on an international crackdown supported by Presidents Clinton and Bush.

Lynn Scarlett, global director at the Nature Conservancy, believes building on previous successes was the key to President Obama's progress.

"It's like he looked at what other administrations had done, and took it a lot further," she says.

"Rather than going for small-scale projects, he has been planning conservation schemes at a very large-scale."

Image copyright Getty Images Image caption The American bison, also known as the buffalo, was named a "national mammal" in the US in 2015

Reform of the Endangered Species Act, which saw a backlog of over 700 species awaiting protection cleared, has received widespread praise from conservation groups.

But Mr Obama's two most recent designations of protected land - Bears Ears in Utah and Gold Butte in Nevada - have been more contentious.

Utah politicians have been up in arms about Bears Ears, with US Senator Orrin Hatch calling the move an "attack on an entire way of life", and the state's attorney general promising to file a lawsuit against the US government.

The area had been under serious consideration for protection by the state - but a bill to do so, which included provisions for some development in the area, failed to pass.

Bears Ears is an important Native American refuge and cultural locale - a group of five tribal governments proposed its inclusion as a national monument to Obama.

Gold Butte is 300,000-acre area in southern Nevada - and the designation aims to protect the ancient rock art, fossils and the desert tortoise habitat there.

But the area is adjacent to property owned by Cliven Bundy and his family.

Mr Bundy and his supporters have previously clashed with the federal government over land use in the area - most notably during a stand-off over $1m in fees for illegally grazing of federal lands.

Supporters of the Bundys held a small rally after the designation last week.

Outgoing Democratic US Senator Harry Reid is fully supportive of the conservation measure, but Republicans from the state have been vocal opponents. Much of land in Nevada is controlled by the US government.

Image copyright AP Image caption In complex deal involving private and federal land, President Obama set aside 67 million acres to help recover the American Greater Sage Grouse, a highly endangered bird

Whether these designations will last under a Donald Trump presidency remains uncertain.

The president-elect's choice for head of the Environmental Protection Agency, Scott Pruitt, has called for the Endangered Species Act to be repealed.

"We are bracing ourselves for a hostile administration," says Jamie Clark, the chief executive of Defenders of Wildlife, a non-profit organisation.

But for now, at least, Mr Obama's conservation record is among the notable legacies of his presidency.

"It's comprehensive, it's marine, it's terrestrial, it's historic, it's high impact," says Jon Jarvis, the director of the US National Park Service.

"He has set a high bar for the world."