I can't find any information about the history of mercury in fish as a public health concern. When was it first recognized that fish contain higher levels of mercury than land animals? How long have we had the technology to measure the amount of mercury in fish?
must... not... write .... L****Y....
Investigations into the presence of mercury in food have been carried out in a comparatively small number of foods in the UK since 1966.
There's considerably more info, several articles, at that page.
From TheOldGreyLady ,possibly paywalled,
Rise in Mercury Is Found In Eaters of Certain Fish By DAVID BIRDJAN. January 14, 1971, Page 74 The New York Times Archives The chemist whose findings last month led to the recall of mercury‐tainted tuna and swordfish reported yesterday that he had found as much as five times the mercury in per sons who ate those fish regu larly compared with those who did not. [...]His discovery was believed to be the first time that high levels of mercury had been found in ocean fish. Before that time, only fresh‐water fish in bodies of water polluted mainly by industrial waste had been, declared unfit for consumption.
and medscape wanders over to Japan, which had a terrible industrial pollution problem,
In 1961, researchers in Japan correlated elevated urinary mercury levels with the features of the previously mysterious Minamata disease. Before the etiology of Minamata disease was discovered, it plagued the residents around Minamata Bay in Japan with tremors, sensory loss, ataxia, and visual field constriction. (See Presentation.) 3
Minamata disease is an example of organic toxicity. In Minamata Bay, a factory discharged inorganic mercury into the water. The mercury was methylated by bacteria and subsequently ingested by fish.
Finally, from a WHO pamphlet, suggesting a start-date for a reasonably reliable test methodology,
The methods summarized in Table I have been selected from a large number of publications. They are typical of the various methods available for analysis of total mercury and its inorganic or organic species. All represent a considerable improvement on the original "dithizone" method. This method was widely used up to the introduction of atomic absorption in the late 1960s. Basically it involved the formation of a coloured complex with dithizone after all the mercury in the sample had been converted to Hg++ compounds by oxidation in strong acids.
A Paper from 1953 describes that "dithizone" methodology.