Are there really only 73 orcas left?

Excuse me, could you please clarify something for me? The paragraph mentions that there are only 73 orcas left. Is this a definitive number, or is it an estimate? If it's an estimate, what is the range of possible numbers? Also, are these orcas from a specific pod or region, or is this a global count? It's essential to understand the accuracy and context of this information, as it could have significant implications for conservation efforts. Thank you for your time.