Bentho-pelagic fish utilize both demersal (bottom) habitats and shallower portion of the water column, often as part of diel migrations whereby fish feed in shallow water at night and move to deeper water to form schools during the day. Four currently or historically important species of bentho-pelagic fish in Puget Sound are the Pacific hake (Merluccius productus), the Pacific cod (Gadus macrocephalus), the Walleye pollock (Theragra chalcogramma) and the spiny dogfish (Squalus acanthias). Three of these species (Pacific hake, Pacific cod and Walleye pollock) were included in a petition for federal listing under the Endangered Species Act in 1999.
