Nursery habitat use for larval and juvenile Pacific herring Clupea pallasii in Miyako Bay on the Pacific coast of northern Japan

To clarify nursery habitat use for larval and juvenile Pacific herring Clupea pallasii, we collected eggs, larvae, and juveniles at several sampling sites in inner Miyako Bay from 2012 to 2016. Adult C. pallasii used sea grass beds on the west side of inner Miyako Bay as a spawning area. In contrast, their offspring grew up to approximately 100 mm in total length (TL) on the east side of the inner bay, where they stayed until July. C. pallasii seemed to leave the nursery area on the east side of the bay with the rise in temperature in August. Therefore, C. pallasii shifted habitats with ontogenetic development, from the west side of the inner bay in the egg stage, to the east side of the inner bay in the larval and early juvenile stages, and then to the central bay area in the later juvenile stage. Environmental surveys showed lower salinity near the bottom of the east side than the west side of inner Miyako bay, suggesting that larval and juvenile C. pallasii appeared to use the area with low salinity on the east side of Miyako Bay as a nursery.