Prior to the damns, timber mills, irrigation ditches and other habitat destroying forces, the annual return of Chinook salmon to the Columbia river was counted in the 10's of millions. There were so many salmon that they could only estimate the run was approx 60 million (based on the fact that they caught 20 million).

600,000 salmon is not a record return - it's pathetic. It's the best that modern technology has been able to produce, but it's only 1% of mother nature's capacity.

That's not just a clue, it's a fact.