Effects of river flow on larval growth and survival of Japanese seaperch Lateolabrax japonicus (Pisces) in the Chikugo River estuary, upper Ariake Bay
Effects of river flow on larval growth and survival of Japanese seaperch Lateolabrax japonicus (Pisces) in the Chikugo River estuary, upper Ariake Bay
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DOI：
10.1111/j.1095-8649.2006.01235.x
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发表时间：
2006-12
影响因子：
2
通讯作者：
J. Shoji;T. Ohta;Masaru Tanaka
中科院分区：
文献类型：
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作者：
J. Shoji;T. Ohta;Masaru Tanaka
1990~2000年，在有莱克湾上游的奇库戈河口，调查了花斑石斑幼鱼和幼鱼的丰度和生长历史。采用生物截距法，利用矢状面耳石显微结构，反算出仔鱼体长达15 mm标准体长的L S的幼体生长量。在体型为14 mm L时，体长增长率下降。通过Chikugo河的高淡水排放与上游Ariake海湾的高温有关，幼虫在那里度过他们的浮游生活。幼虫从孵化到15 mm的平均历期(D15)在48·8~76·2d之间变化，与估计的平均气温历史[幼虫从孵化到15 mm期间经历的平均日温度(°C)，T15]呈负相关。仔鱼和幼鱼的平均丰度(m-2)在T15、D15和淡水排放量处于中等水平的年份最高。尽管丰度与这两个变量中的任何一个变量都不相关，但如果剔除在河流流量最高的年份(1990、1991和1998年)收集的数据，丰度与D15之间存在指数关系。通过Chikugo河的淡水流量的增加可能通过两种方式增加或减少日本海鳗的补充：1)它可以通过增加温度和仔鱼的生长来增加补充的可能性，2)高流量也有可能通过增加幼体向海的扩散、由于减少浑浊而减少捕食和由于河口浮游动物猎物丰度的减少而减少饥饿，从而降低向河流迁徙的可能性。
The abundance and growth history of larval and juvenile Japanese seaperch Lateolabrax japonicus were investigated in the Chikugo River estuary, upper Ariake Bay, from 1990 to 2000. Growth during the larval period (up to 15 mm standard length, L S , the size at recruitment into the estuary) was backcalculated using sagittal otolith microstructures by the biological intercept method. Growth rates in length declined at body sizes >14 mm Ls. High freshwater discharge through the Chikugo River was associated with high temperatures of the upper Ariake Bay where the larvae spend their planktonic life. Mean larval stage duration (days) from hatch to 15 mm (D 15 ) varied between 48·8 and 76·2 days and was inversely correlated with the estimated mean temperature history [mean daily temperature (° C) experienced by the larvae during the period from hatch to 15 mm, T 15 ]. Mean abundance (number m -2 ) of larvae and juveniles was highest in years when T 15 , D 15 and freshwater discharge were at intermediate levels. Although the abundance was not correlated with either of these variables, an exponential relationship between abundance and D 15 was found when data collected during the highest river discharge years (1990, 1991 and 1998) were excluded. The increase in freshwater discharge through the Chikugo River probably had the potential to enhance or diminish Japanese seaperch recruitment in two ways: 1) it could increase recruitment probability by increasing temperature and larval growth and 2) high river flow also had the potential to decrease the probability of immigration into the river by increasing larval seaward dispersion, predation due to decreased turbidity and starvation due to decreased zooplankton prey abundance in the estuary.