When it comes to mitigating the effects of the oil spill, President Obama, like his administration's federal response, has focused on the country's coastlines.
Meanwhile, government agencies have repeatedly underestimated the amount of oil spewing into the Gulf of Mexico. (The newest estimate, released Tuesday afternoon, is 35,000 to 60,000 barrels a day, some seven to 12 times the original estimate, and even so, "the upper number is less certain," according to Energy Secretary Steven Chu.)
The administration only recently -- grudgingly -- acknowledged that much of the oil continues to lurk under the surface, potentially with catastrophic consequences in the months, years and decades to come.
As a result, some marine scientists worry that Obama is basing his conclusions on what's visible, and doesn't really get, even now, just how bad things really are in the Gulf.
Heightening that concern is Obama's new conviction, first expressed Monday afternoon after touring a staging facility in Alabama, that "in the end, I am confident that we're going to be able to leave the Gulf Coast in better shape than it was before."
That is a "ridiculous statement, and worrying," said Susan Shaw, the director of the Marine Environmental Research Institute. "Obviously he has no idea of the consequences, or doesn't want to."
Partly because of the extraordinary sluggishness of the government's response to the sub-surface oil hazard -- a vigorous research initiative only really kicked off last week, some seven weeks into the ongoing disaster -- scientists are a very long way from being able to quantify the damage in the deep ocean.
But they know this much, as Jackie Savitz, a senior scientist with the ocean conservation group Oceana, put it: "The damage is going to be a lot worse than we can see. The oil that's washing up on shore, that's just the tip of the iceberg."
Unlike any other major spill in the nation's history, this one is coming from a blown-out well nearly a mile beneath the surface. The unprecedented use of more than a million gallons of dispersants has made the oil yet more soluble in water. The result is less oil on the surface, and on the coastlines -- at least for now -- but way more oil hovering in the water column, sometimes at great depths.
Out in the deep ocean, sea turtles and other animals are ingesting the oil thinking it's food, larvae from threatened species such as bluefin tuna are inevitably dying in a toxic soup, and so are the tiny but essential organisms that sit at the bottom of the food chain.
"It's really impossible to fully gauge the magnitude of the impacts," Savitz said. "We just know they're big."
"If all you care about is what gets on the beaches, that's one thing," said Shaw. "But we're now poisoning the ocean itself. The deep ocean is what's at risk."
"We're destroying the food web and we're poisoning what's left," she said. "If we remove the bottom of the food web, then everything else on top is going to crash."
Right now, the oil-soaked pelicans, the turtles on their backs, the fouled wetlands, and the dead fish covered in goop are getting way more attention than the plankton casualties, but Shaw said that as a result of the assault on the deep ocean, "there's no doubt we're going to see die-offs in the top predators. It's just a matter of time... We will see fish die-offs and marine mammal die-offs."
"It's infuriating that people are still focused solely, almost, on the shoreline and in-shore damage," said Rick Steiner, a marine conservationist who has been studying oil spills since the Exxon Valdez disaster 21 years ago. "The offshore pelagic damage has now been relegated to 'out of sight out of mind'."
Meanwhile, many marine environmentalists, despite their skepticism about Obama's ability to leave the Gulf "in better shape," are at the same time are hopeful that he is sincere in his efforts.
"There are some of these things that may never recover," said Doug Rader, chief oceans scientist for the Environmental Defense Fund. There's no way to restore ancient reefs, for instance, "unless one has a millennium or two to wait."
But some damage can be remediated -- and some steps can be taken to roll back damage that's slowly taken place over generations, for instance in the Louisiana wetlands.
"We expect a strong and solid downpayment tonight," Rader said.
"What you can do is a lot of environmental offsets," said Steiner, recalling how that was one of the things Alaska did with Exxon money after the Valdez.
"Money from this spill ought to be used to restore the Mississippi Delta and the wetlands and the islands offshore," he said. "Let the Mississippi run. Let some sediment come down and reestablish the Delta."
And yet, as Steiner points out, some effects of the Valdez spill are still being felt. Many fish and wildlife populations have not completely bounced back -- including the indispensable herring, whose population mysteriously crashed four years after the spill, sending ripples throughout the food chain. "They are not recovering, 21 years later," he said. "There's still toxic oil on the beaches."
Obama's "singular objective ought to be full and complete recovery of the Gulf of Mexico, onshore and offshore," Steiner said.
But, he acknowledged: "Prince William Sound will never fully recover from the Exxon Valdez."
Dan Froomkin is senior Washington correspondent for the Huffington Post. You can send him an e-mail, bookmark his page; subscribe to RSS feed, follow him on Twitter, friend him on Facebook, and/or become a fan and get e-mail alerts when he writes.