A few comments on the previous abundance of cod, from https://www.sciencehistory.org/stories/magazine/a-tragedy-wi...

In 1873, French novelist Alexandre Dumas wrote that if every egg reached maturity, within three years “you could walk across the Atlantic dryshod on the backs of cod.” In 1885, the Canadian Ministry of Agriculture said it was not only impossible to exhaust the cod supply, but even to make a noticeable dent in it. “Unless the order of nature is overthrown, for centuries to come our fisheries will continue to be fertile,” the ministry declared.

Humans find a way: https://en.wikipedia.org/wiki/Collapse_of_the_Atlantic_north...