Growing up in California, site of the 1850’s Gold Rush, I was told constantly that “the most successful people during the gold rush just sold shovels.” Very common saying. I even went on trips to mining camps and panned for gold. It’s incredible to see this play out as an adult.https://twitter.com/bascule/status/967214239755657216 …
I've been trying to find more recent studies on it. "It is well known from paleo-sediment analyses that the sardine population off California has been rising and falling for thousands of years with an average period of approximately 55-60 years." https://swfsc.noaa.gov/publications/CR/2000/2000ParrR2.pdf …