London (CNN) While musicians and movie stars campaign vocally to protect our rainforests and oceans, the world's wetlands rarely get the same level of public support. They are in many ways the planet's unglamorous, unsung heroes -- yet by one estimate wetlands are disappearing three times faster than forests.

Our rivers, lakes, marshes, mangroves and peatlands are home to countless species that can survive nowhere else -- from beavers and freshwater turtles to waterfowl and thousands of kinds of fish. They're also a vital long-term store of carbon, helping protect the world from climate change.

"Inland wetlands are the biggest biodiversity hotspot in the world," says William Darwall, head of the Freshwater Biodiversity Unit at the International Union for Conservation of Nature.

But Darwall says these unique habitats are underappreciated. They're widely perceived as a waste of land, he says, better used for something more productive. As a result, vast areas of the world's wetlands are being converted to other uses.

"They're the forgotten realm," says Darwall. "Wetlands are really valuable ... but are suffering the biggest losses of biodiversity of all."

The Ramsar Convention on Wetlands aims to stop the global loss of wetlands and conserve those that remain. It has been ratified by 170 countries, but according to the Ramsar organization, the world has lost more than a third of its wetlands since 1970, and that loss has been accelerating since 2000. It could have very real consequences for us.

Capybara on the banks of the Paraguay river, in Brazil -- the gateway to the Pantanal, the world's largest tropical wetland.

Vital services

Wetlands purify drinking water by filtering out pollutants. Mangroves protect coastal communities against floods, and floodplains can soak up floodwaters when rivers burst their banks. Peatlands -- which include bogs, marshes and swamps -- store almost a third of land-based carbon.

Ramsar says that 40 percent of all species live or breed in wetlands, and even though freshwater habitats take up only about 2 percent of the Earth's surface, there are more fish species in freshwater than in saltwater.

These habitats face countless threats. Mining is impacting wetlands from the Mekong Delta to Alaska, says Darwall. Dams can block animal migration routes, trap sediments, and turn rivers into lakes where some river species can't survive, he adds.

Farmers around the world drain wetlands so they can grow crops there, while pollution and invasive species can devastate native wildlife.

Protecting our wetlands

But there are signs that, with enough support, things can get better. Darwall says that where old dams are decommissioned, nature often reappears. "The good news is, if we do things properly and try to restore things they can return quite rapidly," he says.

He points to Mexico, which has announced it will establish water reserves for the next 50 years, in nearly 300 river basins. As well as protecting water supplies for millions, that will conserve "some of the country's most biodiverse ecosystems and globally important wetland protected areas," according to the WWF.

Jay Aldous, deputy secretary general of the Ramsar Convention, gives the example of a huge mangrove restoration project in Senegal, where 80 million trees have been planted. As well as the mangroves increasing carbon sequestration, he says the communities involved in the planting have seen their fisheries become more productive.

He says that when it comes to protecting wetlands, the first step is for people to understand the value of these ecosystems.

"It starts with each of us having greater appreciation and understanding for the value of wetlands in our lives," says Aldous. "Once we see and understand the value we'll pressure politicians, we'll march in the street, we'll dispose of our trash and plastic more responsibly."

Darwall agrees that awareness is the key. "It's about getting people to love their wetlands," he says. "They can be beautiful places with loads of species, they protect people downstream -- everything about them is good."