By Melissa Gaskill of Nature magazine

More than a year after the Deepwater Horizon disaster gushed oil into the Gulf of Mexico, scientists say that they have been struggling to gain access to the region's rigs and drill ships, hampering their research.

Marine scientists have long been allowed to install instruments on offshore structures. The equipment can deliver vital data that would not be practical to gather in any other way. However, the six-month moratorium on drilling that ended last October has significantly reduced the number of structures available for scientists to work on in the gulf. The oil spill also seems to have created a more cautious climate that has placed a greater bureaucratic burden on scientists trying to access these sites.

Paul Sammarco is part of the Louisiana Universities Marine Consortium (LUMCON) in Chauvin and studies corals in the gulf, particularly those that live on and around oil platforms. When he began planning a research cruise in late 2010, he says that owners of some structures where he had previously worked turned down his requests for access. "It is affecting our ability to do science," he says.

Sammarco stresses that he does not believe the problems stem from the companies' unwillingness to work with scientists. "I feel it is more a matter of working within a new legal framework and atmosphere created by the spill," he says, "which has caused all entities involved to review their restrictions and potential exposure to liability."

Access denied

The Shell Exploration and Production Company had agreed to grant Sammarco access to its Cognac platform, but was still requesting information and discussing access details on the morning of 10 May, the day Sammarco's research cruise set sail. Ultimately, Sammarco was unable to access Shell's platform, and was also denied access to platforms owned by ExxonMobil and Arena Offshore, a company based near Houston, Texas, on whose rigs he has conducted research in the past.

According to Arena's general manager of operations, Debbs Nelson, his company has not made changes to the terms of its access agreements. "We require a certain level of indemnification for our protection, and that has always been in place. If a party is willing to submit to that, then normally we don't have a problem with them coming out and doing their work." Shell Oil Company has not made changes to its access agreements either, says Kelly op de Weegh, a spokesperson for Shell in Houston. ExxonMobil did not respond toNature 's requests to comment.

But Quenton Dokken, president of the Gulf of Mexico Foundation, a non-profit conservation organization based in Corpus Christi, Texas, says that the terrorist attacks of 11 September 2001 caused companies to look more carefully at liability and risk of such attacks, and Deepwater Horizon has renewed their concerns. "Companies were concerned that if they work with us and one of our people is injured, how do they protect themselves from liability? There are legitimate hazards to being around these structures."

"The scientists have my sympathy, but I can see the other side, too," he adds. After last year's enormous oil spill, he explains,"There has been a feeding frenzy in litigation, the government basically shut down operations in the gulf, and everyone is wondering if they'll be the next target. The science community would be naive to think that companies won't step back and reconsider their position on this."

Mark Benfield, an oceanographer at Louisiana State University in Baton Rouge, says that a broader problem has been the lack of rigs at sea, a consequence of the government moratorium on deepwater drilling in the gulf that lasted from May until October 2010. "Without permits to drill, offshore rigs and drill ships weren't in the locations where I would normally work," says Benfield. "The moratorium definitely limited the number of sites that were drilling and therefore potentially available." Benfield adds that with the moratorium now lifted, he is beginning to gain access to sites once again.

Dokken predicts that the situation should eventually improve for researchers willing to tackle the necessary paperwork. "These companies are not opposed to or afraid of science, they encourage it," he says. "But they have to run risk-management scenarios."

This article is reprinted with permission from Nature magazine. It was first published on july 4, 2011.