Abstract
Mierspenaeopsis hardwickii (Miers, 1878) represents an important economic resource for coastal artisanal fishers and small-scale fisheries operations. However, very little is known about the distribution patterns related to environmental factors and migration routes of M. hardwickii. In this study, we employed research vessels to obtain CPUE(w) (weight in catch per unit effort) and CPUE(n) (abundance in catch per unit effort) data in 2018-2019. Our results showed that the largest number was found at 20-40 m in spring and summer, extending in autumn (40-90 m) and shrinking in winter (40-60 m). The scattered distribution pattern of M. hardwickii was observed in spring with sea bottom temperature (SBT) 11-18 °C and sea bottom salinity (SBS) 32-34 and winter (SBT 9-19 °C, SBS 32-35); most individuals were observed in summer (SBT 26-28 °C, SBS 30-31) and autumn (SBT 19-22 °C, SBS 32-35). The annual mean CPUE(w) and CPUE(n) were 3624 g·h(-1) and 799.4 ind·h(-1), respectively. We hypothesize that in spring, most parent cohorts aggregate in Dasha in the southern Yellow Sea, while many cohorts gather in the coastal waters of the East China Sea, with sharply reduced abundance in the offshore deeper waters. In summer, the parent cohorts produced offspring in Lvsi in the southern Yellow Sea, the Yangtze River estuary, and coastal water areas of the East China Sea. In autumn, juveniles in the coastal waters migrated to the offshore water area. In winter, a few individuals were sparsely distributed in the offshore water areas of the southern Yellow and East China Seas, and part of the recruitment in the Taiwan Strait might migrate northward to Yushan and Wentai fishing grounds for the nursery. The present investigations provide baseline data that will enable fishers and policymakers to better manage and conserve this resource for future use.