President Barack Obama's upcoming trip to Cuba on Sunday promises to revive a question raised when the U.S. began normalizing relations with the island nation: As American tourists pour in, what will happen to Cuba's natural environment?

An influx of tourists and businesses will likely bring investment to Cuba, but some experts fear the expansion of tourism, mechanized agriculture and oil exploration could threaten its well-preserved natural ecosystems.

In fact, the Cubans "have a lot to lose in terms of biodiversity, marine and coastal habitat and fish populations if they don’t do things right moving ahead," Daniel Whittle, senior director of the Cuba program at the Environmental Defense Fund, told The Huffington Post.

The uptick in American tourism is already "putting a real strain" on Cuba, he said.

Despite fears of environmental ruin, both Cuba and the U.S. have been working to ensure the restoration of diplomatic ties doesn't come at the expense of Cuba's land and marine ecosystems.

"At the official level, environmental protection is still a high priority," Whittle said about Cuba. "It's something [President Raúl] Castro and his deputies talk a lot about."

U.S. Secretary of State John Kerry has made protecting the environment a central issue in the State Department's negotiations with Cuba.

Of the four agreements signed by U.S. and Cuban officials since the re-opening of relations in 2014, two have laid out plans for environmental protection in Cuba, according to Whittle.

One agreement, signed in November 2015, outlines a planned effort by both countries to share scientific knowledge, collaborate on conservation efforts and jointly "address the causes and effects of climate change" in Cuba, according to a copy of the agreement.

"The agreement provides an unprecedented vehicle for the governments to actually talk to each other and influence each other," Whittle said. Through it, "the U.S. government can influence how science is conducted in Cuban national parks, how well they’re managed and even policy relating to these protected areas."

Noel Lopez Fernandez Coral reef off the coast of Cuba.

A lot to lose

For Cuba, which has been called the "jewel of the Caribbean," the stakes of environmental protection are high.

"It's not a secret that Cuba has some of the best preserved land and waters in the Caribbean," Luis Solórzano, executive director of the Cuba program at the non-profit Nature Conservancy told HuffPost on Friday.

The country has 4,000 uninhabited islands and keys, miles of undeveloped coastline, a huge variety of native species and an extensive coral reef system, according to Whittle. It's no accident they remain well-preserved.

The trade embargo that kept American cars off Cuban roads for half a century has also prevented farmers from adopting high-tech agriculture practices used in the U.S., according to Whittle. And it has kept American tourists off beaches and limited the development of Cuba's oil resources in the Caribbean.

"Because of US-Cuba relations, Cuba hasn’t had access to U.S. technology, hasn't had access to grants and loans from institutions like the World Bank," Whittle said. "So they have a lot to lose in terms of biodiversity."

Noel Lopez Fernandez Cuba's coral reefs are the "heart of the marine ecosystem."

Cuba has vigilantly sought to protect its natural environment over the years.

"The Cubans have been pioneers and really aggressive in declaring protected areas," Solórzano said.

Cuba's commitment to conservation began in 1992, when then-President Fidel Castro announced that his government would confront the "ecological destruction threatening our planet" at the Earth Summit in Rio de Janeiro.

Since then, shrewd environmental management policies have required the Cuban government to protect 25 percent of its marine habitat from development, according to Whittle. (By contrast, the U.S. has only protected between 3 and 5 percent of its marine habitats, according to the Environmental Defense Fund.)

The Cuban government also requires proposals for new developments to undergo a rigorous environmental review process.

Cuba's environmental record isn't perfect, however. While its policies look good on paper, "implementation has been a mixed bag," Whittle said. The country's aging infrastructure has hurt wastewater treatment, agricultural land suffers from soil erosion, and dams have altered water flows in fragile coastal estuaries, according to Whittle.

Cuba also isn't walled off from the world. Cuba does business with many developed countries, including Canada, and its beaches and forests have attracted foreign tourists for decades .

Opening up to Americans will heap new pressures onto Cuba's existing environmental challenges, experts say.

"The question we're asking is 'What if you unleash all these pressures that have not been there?'" Solórzano said.

Noel Lopez Fernandez An underwater look at Cuba's coast.

Striking a delicate balance

If Cuba wants to expand industry on the island without despoiling the environment, the government will have to strike a delicate balance between growth and conservation, according to Solórzano.

"It is about the balance," he said. "How do they balance their economic needs and preserving the natural capital on which they depend?"

Right now, Cuba imports 70 percent of its food at a cost of about $2 billion every year, according to Pedro Sanchez, director of the Agriculture and Food Security Center at Columbia University's Earth Institute. Producing enough food domestically to feed the country's more than 11 million people will require turning some of Cuba's unused land into highly productive crop fields, Sanchez told HuffPost on Friday.

The trick, Sanchez said, will be ramping up food production without causing undue damage to the environment.

"With proper investment and research ... Cuba can increase its food production to the point that it can be nearly self-sufficient without causing significant damage to the coastal ecosystems that we all want to preserve," Sanchez said.

Researchers at the University of Florida and the non-profit Nature Conservancy are working with Cuba's Ministry of Environment to ensure Cuba expands food protection without despoiling the country's land and waters, according to Sanchez.

As a kid, I fished in the coastal waters off Cuba, and I don’t want them messed up." Dr. Pedro Sanchez, director of the Agriculture and Food Security Center at Columbia University's Earth Institute

It's a project that would not have happened had the U.S. not resumed diplomatic relations with Cuba, said Sanchez, who works on the project.

"I doubt very much whether any such thing would have happened before the Obama opening," Sanchez said.

If changing relations with the U.S. have created an opportunity for Cuba to develop economically without sacrificing its rich natural habitats, Solórzano thinks the Cubans can make the most of the opportunity.

"They are really smart, have a vision, care about their environment, and are proud of what they’ve done," he said. "In this country, it can be done."

Sanchez agrees. For him, the future of Cuba's environment is as personal as it is political.

"As a kid, I fished in the coastal waters off Cuba," he said, "and I don’t want them messed up."