There are three species of redfish that are commercially fished on Flemish Cap in the Northwestern Atlantic; deep-sea redfish (Sebastes mentella), golden redfish (Sebastes norvegicus) and Acadian redfish (Sebastes fasciatus). The three target species have both pelagic and demersal concentrations and are all long-lived with slow growth. Because of difficulties with identification and separation, all three species are reported together as 'redfish' and considered a single stock by managers of the NAFO-managed commercial fishery in the 3M division off the eastern coast of Newfoundland, Canada (NAFO 2019).

All three of these species' ranges span the Atlantic and overlap in various marine areas, with populations present in Greenlandic and Icelandic waters of the Eastern Atlantic, and extending as far as Norwegian waters in the case of S. mentella. The species also overlap in their depth range, normally between 100 and 400m. Populations in the Northwestern and Northeastern Atlantic have been shown to be genetically distinct from one another, as have "shallow," "slope," and "deep" groupings that reside at different depths. However, low, but statistically significant rates of introgression have been observed among the various geographical and depth groupings, and hybridization has also been documented among the three species in the Northwest Atlantic (Saha et al. 2017).

Sebastes spp. are harvested by targeted fisheries in NAFO Division 3M and are also retained bycatch in cod and Greenland halibut fisheries. S. mentella and S. fasciatus, known collectively as beaked redfish, account for the bulk of harvest in the targeted fishery, while S. norvegicus is a minority contributor. Bottom trawls and midwater trawls have historically participated in the fishery. Fleets in recent years have exclusively used bottom trawl gear to target redfish in zone 3M, including the Russian fleet (which had most prominently used midwater gear in the past) (Fomin and Pochtar 2019); (NAFO 2020).