Atlantic redfish swim in deep waters at the edge of the major fishing banks and in deep channels carved in the ocean floor. Distinguished by a bony protrusion on the lower jaw and by it's large eyes, the redfish can be found as two distinct species in the northwest Atlantic Ocean. Sebastes Mentella is bright red in colour with a long, well developed beak and is found at depths greater than 200 meters. Sebastes Mentella can reach a length of 60 cm for females and 45 cm in length for males. Sebastes Marinus is found at depths of less than 240 meters and is orange in colour with a small, blunt beak. Sebastes Marinus can reach 70 cm in length for females and can reach 55 cm in length for males. Redfish are preyed upon by cod and turbot and in turn prey upon small fish and crustaceans.
Redfish are viviparous, which means that eggs are fertilized internally and eggs develop in the female's body. After hatching some 25,000 to 40,000 young are retained in the ovaries of the female until the yolk sac of each is adsorbed. Then the young are born alive and free swimming. Mating occurs in September or October and the young are born sometime between April and July. The young redfish are 7 mm at birth and swim freely at the surface waters until they reach 25 mm at which time they move into deeper waters over rocky or mud bottoms.
Essentially the seven main stocks of redfish are considered to be doing fine in terms of their size and magnitude except the St. Pierre stock which is seriously depleted. As well, Atlantic redfish in the Gulf of St. Lawrence are considered to be perilously low and seriously depleted. In 1959 about 389,000 metric tons of redfish were harvested and since then only about 80,000 metric tons of redfish have been harvested each year since 1970. Large, cone-shaped nets are used in both deep water trawls and in mid-water pelagic trawls to harvest redfish. Atlantic redfish are long lived ( 75 years ), late maturing ( 18 years ) and highly vulnerable to the impacts of overfishing. The incidence of mature individuals in harvested catches has decreased by 98 percent since 1984 thus indicating serious implications for the health of redfish stocks. Overfishing seems to be the main cause for this significant decrease in mature redfish individuals being harvested and recruited over time.
photo courtesy of DFO