Hokkaido National Fisheries Research Institute, Fisheries Research Agency, Kushiro, Hokkaido, Japan.
J Fish Biol. 2009 Feb;74(3):604-20. doi: 10.1111/j.1095-8649.2008.02151.x.
Considerable interannual variation in the abundance of larval and juvenile Pacific herring Clupea pallasii was detected in Miyako Bay, on the Pacific coast of northern Japan; abundances were high in 2001 and 2003 and low in 2000 and 2002. Hatch dates and growth rates for larval and juvenile survivors were estimated through otolith analysis. Water temperature and food availability were monitored on the spawning and nursery grounds in the inner part of the bay. The number of spawning females caught in nets set around the spawning ground was recorded during each spawning season (January to May) in 2000-2003. No correlation was found between the number of spawning females and the abundance of larvae and juveniles on the spawning and nursery grounds. The hatch dates of surviving larvae and juveniles were concentrated at the end of the spawning season in 2001 and in the middle of the season in 2003. The larvae experienced relatively high prey concentrations during the first-feeding period in 2001 but low concentrations in 2003. Survival of larvae during the first-feeding period may be a function of prey concentration as well as water temperature. In 2003, low water temperature would reduce starvation mortality during the first-feeding period. In contrast, unfavourable feeding conditions with higher temperatures during the first-feeding period seemed to result in low larval survival in 2000 and 2002. The 2001 larvae grew faster than those in 2003 because of the late hatch dates and the higher ambient temperatures that resulted. Temperature might be a major factor controlling growth rates of C. pallasii larvae in Miyako Bay.
在日本北部太平洋沿岸的宫古湾，发现了幼鱼和幼体太平洋鲱鱼（Clupea pallasii）数量的可观年际变化；2001 年和 2003 年数量较高，而 2000 年和 2002 年数量较低。通过耳石分析估计了幼鱼和幼体幸存者的孵化日期和生长率。在湾内的产卵场和育幼场监测了水温和食物供应情况。2000-2003 年，在每个产卵季节（1 月至 5 月），在产卵场周围的网中捕捞产卵雌鱼的数量被记录下来。在产卵场和育幼场，产卵雌鱼的数量与幼虫和幼体的数量之间没有相关性。2001 年幸存幼虫和幼体的孵化日期集中在产卵季节结束时，而 2003 年则集中在季节中期。2001 年，第一饲料期幼虫经历了相对较高的猎物浓度，而 2003 年则浓度较低。第一饲料期幼虫的存活率可能是猎物浓度以及水温的函数。2003 年，低温会减少第一饲料期的饥饿死亡率。相比之下，在第一饲料期水温较高且食物条件不利似乎导致了 2000 年和 2002 年幼鱼的存活率较低。由于孵化日期较晚和环境温度较高，2001 年的幼虫比 2003 年的幼虫生长得更快。温度可能是控制宫古湾太平洋鲱鱼幼虫生长率的主要因素。
