Testifying before a house panel on Thursday, an official with the National Oceanic and Atmospheric Administration gave the following estimate: About three-quarters of the oil that spilled into the Gulf from BP’s ruptured well is still in the environment.

How does that match NOAA’s previous assertions that “at least 50 percent of the oil that was released is now completely gone” from the environment?

Pay close attention. Emphasis added, this time:

About three-quarters of the oil that spilledinto the Gulf from BP’s ruptured well is still in the environment.

According to The Hill, NOAA senior scientist Bill Lehr said that in their calculations, federal officials used a different estimate of how much oil spilled from the well — an estimate he now acknowledges is less accurate than the numbers that other scientists outside the administration have used. The figure that the government used — 4.9 million barrels of crude — included quantities of oil that never spewed into the Gulf, but were siphoned directly into containment vessels.

(A report released this week by scientists from the University of Georgia used a different baseline figure for its calculations — 4.1 million barrels — in order to more accurately represent how much oil was actually “left” in the Gulf.)

But perhaps most interesting still is another piece of information Lehr disclosed at the hearing: The report had not yet been peer reviewed — which in academia is a process of evaluation intended to ensure quality scholarship.

“Our priority was to get an answer as quickly as possible to incident command,” Lehr explained to the panel; the peer review had been delayed. “We’re hoping to get it out in two months.” The Wall Street Journal, however, noted that at a White House news conference earlier this month, officials had told reporters otherwise.

Here’s what NOAA chief Jane Lubcheco said about the report, from the Aug. 4 transcript:

The report was produced by scientific experts from a number of different agencies, federal agencies, with peer review of the calculations that went into this by both other federal and non-federal scientists.

And here’s what White House energy advisor Carol Browner said at the same briefing:

Can I just add another point? This has all been -- as Dr. Lubchenco said -- been subjected to a scientific protocol, which means you peer review, peer review and peer review.

Why this discrepancy? I’ve called NOAA for comment but have not yet received a response.

Also at issue is what data the government used to back its report. Kate Sheppard of Mother Jones has been dogging that question and has found that even congressional investigators have had a hard time getting a straight answer. (Read the investigator’s e-mail correspondence with NOAA.)

And then I know we pointed this out on Wednesday, but independent scientists kept piling on the research this week about their own spill findings — some outright contradicted the government’s report; others added to what we know about the oil’s movement and location.

The latest, released Thursday, seems to fall into the latter category. Scientists at the Woods Hole Oceanographic Institution measured a plume of dispersed oil that’s “at least 22 miles long and more than 3,000 feet below the surface of the Gulf,” they announced. The Wall Street Journal noted that’s the size of Manhattan.

These scientists, unlike others, found little evidence that oil-eating microbes were consuming much of the dispersed oil, noting that it was dissipating so slowly that it could be in the Gulf for far longer than expected — months, perhaps, but potentially a year or more.

For more, you can read the report [PDF], which the Houston Chronicle has helpfully posted.

As of Wednesday, NOAA’s Lubchenco was still defending her agency’s report:

So in short, we stand by the calculations that we released recently about the oil budget. Some of those numbers we can measure directly. The others are the best estimates that are out there.

It’s unclear whether, after a fourth report, that position still stands. We’ll update if the agency accepts our invitation to comment.