I saw some on an excursion to the Farallones. Just briefly saw their backs as they came up for air, nothing spectacular, but well worth the cold and sea sickness.
I would be suspicious of any claims to returning to "historic levels" - hunting whales got serious in the 1800s, lighting and powering the industrial revolution, long before we counted the numbers sensibly.
> Prior to the late 19th century, blue whales were simply too big and powerful to pursue... Roughly 380,000 blue whales had been killed in all, and the species was at 0.2 percent of its initial numbers.
Given that they couldn't be hunted until fairly recently, and having a decent idea of how many got killed, it should be possible to get very reasonable estimates of pre-hunt populations.
> Among other things, they calculated that there are currently about 2,200 California blue whales today — and that that's about 97 percent of the carrying capacity for the eastern North Pacific. It's a full recovery.
I wonder if that carrying capacity isn't lowered by years of human fishing as well - although based on the rest of the article it seems likely that the researchers did take the full historical context into account.
>Sulphur Bottom - Another retiring gentleman, with a brimstone belly, doubtless got by scraping along the Tartarian tiles in some of his profounder divings. He is seldom seen; at least I have never seen him except in the remoter southern seas, and then always at too great a distance to study his countenance. He is never chased; he would run away with rope-walks of line. Prodigies are told of him. Adieu, Sulphur Bottom! I can say nothing more that is true of ye, nor can the oldest Nantucketer.
Indeed. Prior to steam powered ships and harpoon guns, only the so called 'right whale' (https://en.wikipedia.org/wiki/Right_whale) was hunted by Western nations (by rowing out to them in small boats, sometimes from shore). The right whale is slow, and most importantly, most of them float after being killed.
