Study area, sampling locations, and currents in three areas from four expeditions. Colored circles show 418 sampling effort coordinate points (per sampling gear per station per cruise) during four deep-sea cruises including Sea of Japan Biodiversity Study (SoJaBio, 2010), Kuril-Kamchatka Biodiversity Study (KuramBio I and II, 2012–2016), and Sea of Okhotsk Biodiversity Study (SokhoBio, 2015). The area KuramBio is represented by the two expeditions KuramBio I in 2012 (open abyssal of NW Pacific) and Sea of Okhotsk; SoJ: Sea of Japan; KKT: Kuril-Kamchatka Trench; EKC: East Kuril Current; ESC: East Sakhalin Current; KC: Kuroshio Current; NPC: North Pacific Current; OC: Oyashio Current; OG: Okhotsk Gyre; SC: Soya Warm Current; WKC: West Kuril Current. ArcMap 10.5.1 was used to create this figure.