I liked the imagery, and rather enjoyed the older feel to the voice-over.
As for the figures given, I think that the film-maker and some members of the audience are too concerned with establishing the number, whether for the sake of honesty or for the sake of drama.
A simple way for the film-maker to express his point while remaining completely truthful is to step back from the role of census taker and letting the scientists do the arguing:
"Scientific investigation suggests that humans annually kill up to 100,000,000 sharks."
This statement is completely accurate, yet the film-maker's evocative point retains its clarity.
For what it's worth, I would not be surprised to discover that 100,000,000 is an underestimate, considering the added and undocumented impacts of pollution and increased competition for food with humans, etc.
In sum, I liked the film but would subtly tweak the audio content -- very interesting work, overall, Eric.