BP says it plans to complete the sealing of its Macondo well on Sept. 18 as subcontractor Transocean Ltd.'s "Development Driller III" rig has drilled the final 45 feet of a relief well. The well, in the Mississippi Canyon Block 252, has been sealed from above since July 15, but is being intersected from below to complete Macondo's shutdown. The relief well's drilling was halted for nearly a month, first due to weather impacts, before resuming this week. An estimated 4.9 million barrels leaked from the well, of which BP estimates it captured 800,000. (Oil & Gas Journal, Dow Jones, Sept. 17)

Media accounts since the July capping have generally been portraying the whole affair as anti-climactic (with Esquire going so far in August as to dub it "The Disaster That Wasn't"), since the oil has largely disappeared from human eyes and presumably dispersed. However, as we pointed out a few weeks back, dispersed oil can actually hold greater long-term threats to aquatic life. Furthermore, the latest evidence suggests the oil hasn't entirely dispersed. From NPR, Sept. 10:

Scientists on a research vessel in the Gulf of Mexico are finding a substantial layer of oily sediment stretching for dozens of miles in all directions. Their discovery suggests that a lot of oil from the Deepwater Horizon didn't simply evaporate or dissipate into the water — it has settled to the seafloor.

The Research Vessel Oceanus sailed on Aug. 21 on a mission to figure out what happened to the more than 4 million barrels of oil that gushed into the water. Onboard, Samantha Joye, a professor in the Department of Marine Sciences at the University of Georgia, says she suddenly has a pretty good idea about where a lot of it ended up. It's showing up in samples of the seafloor, between the well site and the coast.

"I've collected literally hundreds of sediment cores from the Gulf of Mexico, including around this area. And I've never seen anything like this," she said in an interview via satellite phone from the boat.

Joye describes seeing layers of oily material — in some places more than 2 inches thick — covering the bottom of the seafloor.

"It's very fluffy and porous. And there are little tar balls in there you can see that look like microscopic cauliflower heads," she says.

It's very clearly a fresh layer. Right below it she finds much more typical seafloor mud. And in that layer, she finds recently dead shrimp, worms and other invertebrates.

How did the oily sediment get there? Joye says it's possible that chemical dispersants might have sunk some oil, but it's also likely that natural systems are playing an important role.

"The organisms that break down oil excrete mucus — copious amounts of mucus," Joye says. "So it's kind of like a slime highway from the surface to the bottom. Because eventually the slime gets heavy and it sinks."

That sticky material can pick up oil particles as it sinks. Joye can't yet say with certainty that the oily layer is from BP's blown-out well.

"We have to [chemically] fingerprint it and link it to the Deepwater Horizon," she says. "But the sheer coverage here is leading us all to come to the conclusion that it has to be sedimented oil from the oil spill, because it's all over the place."

Yahoo News on Sept. 14 ran photos of huge fish kills clogging coastal arteries in Louisiana:

Plaquemines Parish President Billy Nungesser sounded the alarm bells Monday, distributing the photos here to the local media. Nungesser said that no testing is currently planned to determine how the kill may relate to the BP oil disaster, but he pleaded with officials from the Louisiana Department of Wildlife and Fisheries, the Environmental Protection Agency and the National Oceanic and Atmospheric Administration to investigate.

A Sept. 7 Palm Beach Post story on the efforts of oceanographer Mitchell Roffer to track the disaster portrays a near-miss: by a natural fluke, the Gulf Loop Current was weak this year, preventing the oil from being sucked into the trans-Atlantic Gulf Stream, with which it intersects—thereby saving us from a truly global disaster:

From years of studying public data from NOAA, NASA and European Space Agency satellite imagery, Roffer knew that anything entering the northern gulf waters would likely be pulled down around the Keys and South Florida by a current known as the Gulf Loop. So he and his three analysts tracked oil on the Gulf of Mexico's surface to help emergency managers prepare for its arrival...

Contributions from a private donor, a Panama City resort and the Central Florida Offshore Anglers Association helped cover about $2,000 in expenses, Roffer said. "We did it as a public service, because we were concerned about the water and we didn't think that the general public understood what the circulation was in the Gulf of Mexico," Roffer said. "If the loop current had not broken off into an eddy, that water would have gone straight to the Keys."

He estimates the Gulf Loop formed the way it did this summer only three other times in the past 20 years. Only once during that time did it stay so far south for as long, he said — closer to the Yucatan Peninsula and away from South Florida.

We are also hearing (hopefully alarmist) claims by one Dr. Gianluigi Zangari, a theoretical physicist at Italy's Frascati National Laboratories, that the oil disaster has somehow shut down the Loop Current altogether—which could have the effect of shutting down the Gulf Stream itself, with unforeseeable global consequences. However, the accounts never explain the mechanism by which the Loop Current could be shut down. And the accounts all appear on such fringe websites as the conspiranoid Prison Planet and the apocalyptoid Infinite Unknown. The original source seems to be an oddly named New Age prophecy-oriented site, Your Own World USA:

Oceanographic satellite data now shows that the Loop Current in the Gulf of Mexico has stalled as a consequence of the BP oil spill disaster. This according to Dr. Gianluigi Zangari, an Italian theoretical physicist, and major complex and chaotic systems analyst at the Frascati National Laboratories in Italy.

He further notes that the effects of this stall have also begun to spread to the Gulf Stream. This is because the Loop Current is a crucial element of the Gulf Stream itself and why it is commonly referred to as the "main engine" of the Stream.

The account implies that the dispersant Corexit has played a critical role in this supposed phenomenon, but fails to explain exactly how. The closest we get is this:

Approximately 1.8 to 2 million gallons of Corexit have been spayed in the Gulf of Mexico. This is a critical fact as current satellite data of the Gulf feeds, tell Zangari that the Loop Current in the Gulf of Mexico has clearly stalled. This due to environmental impacts from a man-made introduction of oil, which were then compounded by other agents (Corexit and so on).

We'd like to hear directly from Dr. Zangari—does anyone have a line to him?

See our last posts on the Gulf of Mexico disaster.

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