THE U.S. ALLOWED DRILLING WITHOUT NEEDED PERMITS

The federal Minerals Management Service gave permission to BP and dozens of other oil companies to drill in the Gulf of Mexico without first getting required permits from another agency that assesses threats to endangered species — and despite strong warnings from that agency about the impact the drilling was likely to have on the gulf.

Those approvals, federal records show, include one for the well drilled by the Deepwater Horizon rig, which exploded on April 20, killing 11 workers and resulting in thousands of barrels of oil spilling into the gulf each day.

The Minerals Management Service, or M.M.S., also routinely overruled its staff biologists and engineers who raised concerns about the safety and the environmental impact of certain drilling proposals in the gulf and in Alaska, according to a half-dozen current and former agency scientists.

Those scientists said they were also regularly pressured by agency officials to change the findings of their internal studies if they predicted that an accident was likely to occur or if wildlife might be harmed.

Under the Endangered Species Act and the Marine Mammal Protection Act, the Minerals Management Service is required to get permits to allow drilling where it might harm endangered species or marine mammals.

The National Oceanic and Atmospheric Administration, or NOAA, is partly responsible for protecting endangered species and marine mammals. It has said on repeated occasions that drilling in the gulf affects these animals, but the minerals agency since January 2009 has approved at least three huge lease sales, 103 seismic blasting projects and 346 drilling plans. Agency records also show that permission for those projects and plans was granted without getting the permits required under federal law.

“M.M.S. has given up any pretense of regulating the offshore oil industry,” said Kierán Suckling, director of the Center for Biological Diversity, an environmental advocacy group in Tucson, which filed notice of intent to sue the agency over its noncompliance with federal law concerning endangered species. “The agency seems to think its mission is to help the oil industry evade environmental laws.”

Kendra Barkoff, a spokeswoman for the Minerals Management Service, said her agency had full consultations with NOAA about endangered species in the gulf. But she declined to respond to additional questions about whether her agency had obtained the relevant permits.

Federal records indicate that these consultations ended with NOAA instructing the minerals agency that continued drilling in the gulf was harming endangered marine mammals and that the agency needed to get permits to be in compliance with federal law.

Responding to the accusations that agency scientists were being silenced, Ms. Barkoff added, “Under the previous administration, there was a pattern of suppressing science in decisions, and we are working very hard to change the culture and empower scientists in the Department of the Interior.”