My theory is that Europeans have been fishing the Grand Banks for a very long time. A good strategy for long range fishing expeditions might have been to stage the return voyage from New Foundland to repair the clinker hulls and dry/salt the catch prior to the long voyage home.
It is a tenable theory.
Good fisherman aren’t going to broadcast where the good fishing holes are.
That said, depending on relations with the natives, it might have been wise to not be on shore too long which may have discouraged landing for anything other than water. So it is possible that fishing occurred without leaving much of an archaeological footprint.
That said, one of the inexplicable things about the excavation of the Norse sites in Greenland is the almost complete absence of fish bones, which would either rule out the Norse engaging in the fishing or require something really weird being done with the bones.