“So later when things began to loosen up and relations warmed, there was a network of people who knew each other quite well who had actually had dinners together and been to each other’s homes,” said William Reilly, the head of the Environmental Protection Agency under President George H.W. Bush. “That is enormously constructive.”

The researchers understand that anything involving Cuba is going to be controversial. A decision to grant President Raul Castro’s daughter a visa to attend an academic conference in San Francisco this week sparked a wave of criticism from Cuban-American groups, calling her an enemy of democracy. But the researchers say their work is focused on science, not politics. Their cooperation will serve as a foundation for future dialogue, they say.

“The political relationship at some point, in five years, 50 years, 500 years, whatever it is, will change,” said Vaughan Turekian, an atmospheric geochemist and chief international officer at the American Association for the Advancement of Science.

In a rare move last year, the Environmental Defense Fund received State Department approval to bring a senior official from the National Oceanic and Atmospheric Administration to Cuba to meet with officials about rebuilding fish stocks for species of fish that populate the region.

Oil is a key area of cooperative interest.

Scientists have helped facilitate talks between the nations as the specter of an oil spill has raised concerns in both of them.

Cuban oceanographers reached out to their U.S. counterparts after the 2010 BP spill to help them gain reassurances that the U.S. government would step in should the gushing petroleum come near Cuban shores.

“The ocean doesn’t have borders. It’s more about the currents. It’s more how nature works and which are the vulnerable species,” said Roberto Perez, a scientist at the Antonio Nunez Jimenez Foundation of Man and Nature in Havana. “Fortunately, it didn’t come to our waters, but the idea really opened up the window of opportunity for the governments to talk.”

Those conversations have increased as Cuba prepares to drill for oil just 70 miles from the Florida Keys.

Last year, the U.S. Treasury Department granted a group of environmentalists and drilling experts, led by the Environmental Defense Fund, permission to travel to Cuban to meet with top officials at the Ministry of Basic Industry, which regulates the energy sector, as well as the state-run petroleum company. The group included Reilly, the co-chair of a bipartisan commission that investigated the 2010 BP spill. He said his goal was to share the commission’s findings with Cuban officials, who had no experience regulating offshore oil and gas, in hopes that they wouldn’t make the same mistakes that led to the BP disaster.

When he returned to the United States, Reilly briefed the Bureau of Ocean Energy Management, Regulation and Enforcement and other administration agencies, whose officials, Reilly said, were very interested to learn that the Cubans were reading the Interior Department’s regulatory reports and planned to adhere to American standards.

“That was not known,” he said.

U.S. officials also have engaged with the International Maritime Organization, which has sent technical teams to Cuba to evaluate its oil drilling procedures, and Cuban and U.S. officials met in the Bahamas in December along with officials from Mexico and Jamaica to discuss disaster plans. A similar meeting was held in Trinidad and administration officials say more will come.

“In fact, we’re all comfortable all the entities that would need licenses to respond appropriately either have them or are in the process of getting them at this point,” said a senior administration official, who requested anonymity in order to speak freely.

Reilly notes that his delegation spent several days speaking directly with top Cuban officials and was able to gather specific details about Cuban plans that may not have been discussed at other multinational meetings.

“On the oil and gas issues, we’ve been moderately successful in getting the two governments to start talking with each other,” said the Environmental Defense Fund’s Whittle, who helped lead the trip and had several meetings with administration officials.

There are still considerable obstacles to be overcome. In addition to needing visas to travel to the United States, Cuban scientists work with fewer resources. The Internet also is not easily accessible.

In February, Fabian Pina, a scientist with Cuba’s Center for Coastal Ecosystems Research in Cayo Coco, Cuba, was awarded a $150,000 Pew Fellowship in Marine Conservation to study goliath grouper populations in Cuba, the first time a Cuban researcher has received the prestitigous grant, a kin, in the marine science world, to winning a MacArthur “genius grant.”

But Pina was supposed to be in the 2011 class. It took months to get proper approvals from U.S. officials, who were concerned the grant money would be taken or taxed by the Cuban government.