I doubt there are none left, I mean the ocean is what like 90% of the world or something....
Well considering that the species -was functionally extinct in 1999(with only about 13 animals alive at the time), it's quite possible that in just 7 years the whole species is completely wiped out.
Also this was a River species - not an ocean going species. Which means it likely had a smaller population to start with than most ocean going dolphin species of equal size.