The woman who was a key figure in the federal government's response to the oil spill in the Gulf of Mexico in 2010 said Wednesday she will leave her post at the end of February.

"I have decided to return to my family and academia," Jane Lubchenco, administrator of the National Oceanic and Atmospheric Administration, wrote to NOAA employees.

No successor was immediately announced for Lubchenco, who has held the job since 2009. She became well-known to the public for her role in response to the BP oil spill off the coast of Louisiana in April 2010.

Her agency was accused of accepting for too long the oil company's low estimates for the amount of oil leaking. It also was criticized for a report saying that by August of that year most of the spilled oil was gone, or at least not visible. The agency said much of it had dispersed naturally, had burned or was removed.

A few weeks later, a study by independent scientists reported an invisible, 22-mile underwater plume of oil ingredients. And NOAA acknowledged the deepwater oil was not degrading as fast as they initially thought.

Still, Lubchenco was praised Wednesday by the Ocean Conservancy. "Dr. Lubchenco and NOAA were quick to respond to the BP Deepwater Horizon oil disaster and continue to play a pivotal role in ensuring that the Gulf region, including the marine ecosystem, is restored," said interim president and CEO Janis Searles Jones.

Lubchenco also oversaw in 2010 the controversial transition to a new fishery management system in New England that allots fishermen individual shares of the catch, which they pool and manage in groups.

The system aimed to give fishermen flexibility to fish when the market and conditions were good, and free them from being restricted to an ever-dwindling number of days they were allowed to fish. And it pleased environmentalists because it established hard, enforceable catch limits to better prevent overfishing.

A marine ecologist and environmental scientist by training, and a former president of the American Association for the Advancement of Science, Lubchenco is one of several prominent scientists hired by the Obama administration.

She was a professor at Oregon State University when the president appointed her in 2009. She said in her email Wednesday that "as many of you know, my home and family are on the West Coast."

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Jay Lindsay in Boston and Seth Borenstein in Washington contributed to this report.