How many bird victims were there in the oil spill in San Francisco Bay? How do people decide whether an oiled bird is curable?

R = reporter; B = Dr. Bennet (the zoologist)
R: Welcome back on "Things You May not Know" to continue our questions on the bird
section, Dr. Bennet, are oil spills a big threat to seabirds?
B: Oh, more than most people would imagine. Last Sunday an oil tanker sank in Russia’s Kerch Strait, and 30,000 seabirds died of oil contamination. Only two days later, a tanker crash in San Fransisco Bay killed 500 birds and another 700 oiled birds are still under medical care.
R: Poor things!
B: I know, it could be pretty tragic.
R: Dr. Brennet, just now you told us it takes a lot of work to save an oiled bird. So exactly how do you do that?
B: We have to use chemicals, and the cleaning has to be done with caution. You see, oil clots when it gets on the plumage and it destroys the airtight insulation.
R: What does that mean, Dr. Bennet?
B: It means the feathers are no longer waterproof. It seeps through the feathers. Instinctively the bird will try to clean its feathers with the beak. But the self-cleaning behavior can cause it to take the oil into its body.
R: So the bird is poisoned as a result?
B: Exactly. At this point, the only way to save the animal is to feed it through a tube to its stomach a liquid mixture of vitamins and medicine. And the medicine helps to remove the oil from inside the body.
R: But tell us, Dr. Brennet, is it possible that the oiled bird is so badly oiled that its conditions turn out to be fatal and we simply can’t save it?
B: It sure happens. Before we actually start the cleaning process, we need to decide the extent of contamination. We analyze blood and feather samples. Any birds judged too weak to survive a full cleaning are euthanatized. You know, if there’s nothing we can do, at least we can offer them a painless death.