Commercial fishing practices on offshore juvenile flatfish nursery grounds on the Grand Banks of Newfoundland

Analyses of the 1985 to 1989 juvenile flatfish survey data from the Grand Bank off the east coast of Newfoundland has delimited two major areas of juvenile American plaice, Hippoglossoides platessoides, concentrations: one on the northern slope and one on the southern edge of the bank. A major concentration of juvenile yellowtail flounder, Limanda ferruginea, was distributed in the area of the Southeast Shoal on the southern Grand Bank. Juveniles of both species shared their distribution with their adult population and there was some overlap by juveniles of both species on the southern Grand Bank. These areas of concentrations are hypothesized to be oceanic nursery sites for both Grand Bank species.The northern plaice nursery area is fished heavily by the Canadian otter-trawler fleet because the majority of the adult population is located in this area. The southern nursery area for plaice is fished heavily by many otter-trawl fleets of other nations since it is located outside of Canada's 200-mile fishing boundary. The southern nursery area for juvenile yellowtail flounder straddles the 200-mile boundary and, consequently, is fished heavily by Canadian (inside) and non-Canadian (outside) fleets. The implications of these dual fisheries on the southern Grand Bank is discussed in terms of discarding of under-sized fish by the Canadian fleet inside the 200-mile boundary and the directed effort on juveniles outside the boundary.