Salmo raises an interesting point that has bothered me from an ecological perspective. In times of great resource abundance we certainly had fewer people but we also had many resources we did not harvest. All the benthic species, except, for example, halibut on landlines. But the high seas species were essentially unharvested as were the benthic species.

Take for example clams. What would be the water quality status vis-a-vis algae blooms in PS if no subtidal shellfish were harvested? A lot cleaner, I'll bet. We really don't know how, for example, albacore affected salmon but does the current extensive harvest of them depress salmon somehow? I don't know.

But I am confident that the ecosystem, when harvest removals were essentially limited to land-based, was a whole lot different and our removals of these previously unaccessible resources has to have had an impact.