Measuring number of dead ducks caused by oil spill proves difficulty, Times-Picayune, October 03, 2010:
Some toxic components of the oil known as polycyclic aromatic hydrocarbons (PAHs) have a shelf life of up to 50 years. ...
"University of Miami researcher Jerald Alt has the right analogy: "We've been put in a movie, and we don't know the ending."
Measuring the amount of oil is also impossible because the dispersant they used sank it all