Long-Term Changes in the Distribution and Abundance of Nine Deep-Water Skates (Arhynchobatidae: Rajiformes: Chondrichthyes) in the Northwestern Pacific

The Aleutians and Beyond: Distribution, Size Composition, and Catch Dynamics of the Aleutian Skate Bathyraja aleutica across the North Pacific

The results of long-term (1948-2021) studies on the spatial and vertical distribution, dynamics of abundance, and size composition of the Aleutian skate Bathyraja aleutica in the North Pacific Ocean are presented. Maximum densities of this species were characteristic of the eastern Bering Sea slope, off the central Aleutian Islands, consisting of the Pacific waters off southeastern Kamchatka and the northern Kurils, and northeastern Sakhalin. This species was most abundant at depths of 100-600 m; in the cold months, B. aleutica migrates to greater depths for over-wintering, and in warm months it feeds at shallower depths. Bathyraja aleutica was most common at the bottom, at temperatures around 3 °C. The total length of individuals ranged from 9.6-170 cm, with a predominance of skates with a length of 50-100 cm. Males did not differ significantly from females in body weight and length. The maximum values of the condition factor were typical for the autumn-winter period. Across years, there was an increase in Aleutian skate catch rates from the western Bering Sea and the Sea of Okhotsk, and a decrease in the Pacific waters off the Kuril Islands and Kamchatka, as well as in Alaskan waters.