As a sample for the kind of Yankee activity in the Bay Area in 1852. In this case, Oakland prior to its becoming a town in 1853, one of the more prominent business activities was the killing of waterfowl.  Below is a brief commentary about that business with three hunters and the number of birds they killed in a month – over 1,400, which netted them $771.18  This is from Wood’s “History of Alameda County“.

The supply of game was practically unlimited as the following items will show.
In February, 1852, Moses Wicks, T. W. Mulford, and the Smiths, sent to market,
the fruits of their own guns, in that month, one hundred and twenty-five pairs of wild
geese; fifty-three pairs of canvas-back ducks; sixty-nine pairs of small ducks; fifteen
pairs of widgeons; forty-one pairs of spoonbills; twenty-seven pairs of teals; sixty-three
pairs of broad-bill ducks; one hundred and ninety-two curlews; two hundred and
seven plovers; forty-eight dowitches; one hundred and fifty-six “peeps”; forty-eight
snipe; and one rabbit, being in all fourteen hundred and twenty-three head, for which
seven hundred and seventy-one dollars and eighteen cents were received.

The business eventually wiped out tens of millions of birds around the Bay Areas and especially on the Farallon Islands most of which had to do with feathers for women’s high society hats. A small piece of good news is that the bay’s bird population has doubled since 2,000, yet it is still close to 90% less than it was when Yankees first arrived in 1850.  There are still major concerns about the ongoing mercury pollution of the bay that is still coming down from the Sacramento Delta as a result of the gold mining from that era. And of course, this attack on birds became more about the ongoing attempts to completely fill in the bay as developers sought ever more people to live here.  For a good summary check out the Natural History of San Francisco Bay.