Depending upon the species, fishers may harvest along the ocean floor for many rockfish and other groundfish, while hake, pollock, and some rockfish species (i.e. greenies and brownies) are targeted with mid-water trawls.
2007, R. Quentin Grafton, Harry W. Nelson, Bruce Turris, “How to Resolve the Class II Common Property Problem? The Case of British Columbia's Multi-Species Groundfish Trawl Fishery”, in Trond Bjørndal, Daniel V. Gordon, Ragnar Arnason, U. Rashid Sumaila, editors, Advances in Fisheries Economics: Festschrift in Honour of Professor Gordon R. Munro, Oxford: Blackwell Publishing, page 61