Pacific cod and walleye pollock
By Wyatt Fournier, NOAA Fisheries, on the Northwest Explorer
Last month, the narrow continental shelf in the Southeast Gulf of Alaska grid produced adequate catches of rockfish and arrowtooth flounder. In contrast, the wide shelf in the Western Gulf of Alaska grid has been producing large catches of Pacific cod (Gadus macrocephalus) and walleye pollock (Theragra chalcogramma). These highly important commercial fish of the Gadidae family are the most abundant species of cod in Alaskan waters. The Alaska pollock landings are the largest of any single fish species in the United States.
Last month, both species were slightly smaller and it was very difficult to tell them apart. As both species grow throughout the summer, their body morphology continues to develop and it is much easier to distinguish between the two. The Pacific cod, sometimes called a gray cod, has a deeper body and light brownish color as a juvenile. As adults, this species will develop a long chin barbell. The juvenile walleye pollock have a slender body, a silver tint, a slightly upturned mouth, and a larger eye diameter. As an adult, this species will become fish sticks.