There was a huge oil spill on the coast of France quite a while back (70s? 80s?)? I remember everyone fretting about the shell-fish and fishing industries as well as the water-fowl at the time, and many predicting that they would never recover. Turns out that most forms of sea life and water fowl in the area recovered within a year.
So, with that completely unsupported evidence, I say, with the confident authority possessed only by the ignorant... ********** the birds, they'll get over it".