Oh yeah. I still remember all the “dont eat the fishes” campaigns because of mercury fears from the ‘70s or was it early ‘80s? Anyhoo, sometime around in that general time frame.
Yep, it started back in the '70s not long before the left hijacked sensible resource Conservation and turned it into a dirt-worshipper cult. A few bad examples were used to propel the budding environmental movement into a political force which was used to advance the cause of Marxism/Socialism everywhere, and especially to weaken the Western industrial base.
Even though the Cold War is allegedly over, that process continues to our detriment, and to the glee of Globalist Socialists everywhere.
The real emissions problems have been handled (here) for the most part, and new ones can be remedied as they become apparent.
Unfortunately, those standards are moving targets.
We do a lot of fishing and are very much aware of the continuing situation of mercury in fish. Here's a much more recent consumption guideline for mercury & PCB's in fish: