There were several ways of catching salmon.
First, using a rod and line in a river. This was and still is a very sought-after 'sport' and an important economic activity because it attracts wealthy customers and provides employment in rural areas.
Second, on rivers using boats to lay a net round in a circle and pull it in.
Third, on beaches using stake nets designed to trap the fish at high tide and then to be emptied at low tide.
Fourth, by boat at sea.
Fifth, by assorted illegal methods of poaching.
If you can supply his name, approximate year of birth and where he lived when he was not away at the fishing, we might be able to make a stab at finding him.