According to the Fishing Rules for the Far East Fishing Basin, Alaska (walleye) pollock is harvested only with mid-water trawl.
Size of the mid-water trawls used in the pollock fishery can differ, and is in connection with vessel’s size. For the large-scale fleet, the vertical opening of a standard mid-water trawl is about 60-65 meters, horizontal opening – 100-110 meters. Trawl opening decree can be handled with trawling speed, length of the trawl warps, and weights set on the trawl.
Pelagic trawls target big shoals of pollock. Pollock is usually trawled at a speed from 3 to 3.5 node at a depth of 200-300 meters in the pelagial. To adjust the depth the mid-water trawl is equipped with sonar and other tools allowing to control not only the depth of immersion but a filling degree of the net.
Mid-water trawl does not contact with the bottom and, thus, has minimum negative impact on the benthic ecosystem.
The Fishing Rules establish mandatory requirements for the fishing gear (mid-water trawl) in order to minimize the impact on the environment. Inner mesh size shall be not less than 100 mm for a net of nylon and not less than 110 mm for all the other kinds of material. The mesh size requirement is set on the basis of the measures adopted by the commercial pollock size of 35 cm.
Pelagic trawl is designed in such a way that pollock juvenile (fish of the size less than 35 cm) come out of the trawl, also through a special insert with selective "mirror" arrangement of the mesh. Use of selective insert, which is mandatory for the mid-water Alaska pollock fishery, is an important solution for the improvement of the selectivity of fishing gear. Recent studies confirm the high efficiency of the applied selective insert.
Besides mid-water trawl, Alaska pollock is harvested with Danish seiners in the coastal fisheries mainly off the west coast of Kamchatka.
Bottom trawl fishing for pollock is completely banned in the Russian EEZ waters.