ASmith1946 extrapolated from data available...

> It may also have been due to confusion with mackerel. Perhaps they
> were catching tuna but considered them mackerel? One early name for
> tuna in the US was "Spanish mackerel." And some early recipes for tuna
> said cook it like a mackerel.
>
I suspect that tuna awaited the arrival of canning and refrigeration to
become popular in markets where it was other than an inshore 'fresh" fish.
For small boat netters, a school of tuna was as damaging to equipment and
as impossible to handle as a pod of whales. Even in the 50s, when big tuna
remained plentiful, some harvesters still harpooned as well as long lined.

As for salting, all but the smallest tuna have to be bled, sliced, laborous
and time consuming, to be salted, and "salt tuna" was never well known.
Cousin mackerel (and "Spanish Mackerel" to me is a small mackerel, with
the big ones, harder to prepare and not well regarded for eating, are "King
mackerel" or "Kingfish") are small enough to split and salt.

Cod, almost without oil, was the blessed fish, large enough to feed many,
yet easy to preserve.

TMO