Correct me if I'm wrong but when Parker said selective I don't think he is refering to wild or hatchery, rather species. Sportsmen can't be specific or selective when fishing for wild or hatchery either till you can see the fish. Thats why we have catch and release of wild or non targeting fish.

Gillnets and Trawlers are very specific in the sepecies they target. It is all in how you target the species.

Factory Trawlers are are equiped with some of the most advanced nettings and sonar system . No it can't differentiate a wild or hatchery fish ( it really doesn't matter anyways , since the species they target don't have a hatchery origin) but it will do a lot better job then you and your boat will.

Reason for Trawlers, Trollers, Gillnets, Seiners, Long liners, are because they are targeting a selective fisheries. At the same time you you can use these vessels to be non selective but I have not seen any of that for more then 15 years , not by American fisheries .