摘要
This study focused on the causes of the variation in microphytobenthic biomass and the effects of this variation on macrobenthic animals in the western Seto Inland Sea, Japan, where the importance of microphytobenthos as the primary food source for benthic animals has been recently reported. We investigated the microphytobenthic biomass together with light attenuation of seawater, phytoplanktonic biomass, macrobenthic density and biomass at eight stations (water depth = 5–15 m) during four cruises in 1999–2000. The increased light attenuation coefficient of the water column associated with increased concentration of the phytoplanktonic Chl-a caused a decrease in light flux that reached the seafloor. The biomass of the microphytobenthos within the upper 1 cm of the sediment, 1.9–46.5 mg Chl-a m−2, was inversely correlated with the phytoplanktonic biomass in the overlying water column, 10.9–65.0 mg Chl-a m−2. Thus, interception of light by phytoplankton is considered to be a main cause of the variation in the microphytobenthic biomass. The microphytobenthos biomass showed a significant positive correlation with the macrobenthic density (78–9369 ind. m−2) and biomass (0.4–78.8 gWW m−2). It appears that the increase in oxygen production by the microphytobenthos allowed macrobenthic animals to become more abundant, as a consequence of oxygenation of the organically enriched muddy sediments (14.5 ± 2.69 mg TOC g−1). This study suggests that the variation in the microphytobenthic biomass is influenced by the phytoplanktonic biomass due to shading effect, and the balance between these two functional groups might affect the variability in the macrobenthic density and biomass.
摘要译文
本研究侧重于日本濑户内海西部小潮间带生物量变化的原因及其对大型底栖动物的影响，小型底栖动物作为底栖动物的主要食物来源的重要性已经被最近报道。我们调查了海水微生物生物量，海水淡化，浮游植物生物量，在1999 - 2000年的四次巡航中，八个台站（水深\x3d 5-15米）的大型底栖生物密度和生物量。与浮游植物Chl-a浓度升高相关的水体光衰减系数增加引起到达海底的光通量减少。沉积物上部1cm内的底栖动物生物量，1.9-46.5mg Chl-am-2与上覆水体中的浮游植物生物量呈负相关10。9-65.0mg Chl-a m-2。因此，被浮游植物遮挡的光被认为是小叶期生物量变化的主要原因。底栖生物生物量与底栖生物密度（78-9369 ind.m-2）和生物量（0.4-78.8 gWW m-2）呈显着正相关。看起来，小型底栖动物的氧气产量的增加使得大型底栖动物变得更加丰富，作为有机物富集泥质沉积物（14.5±2.69mg TOC g-1）的氧化的结果。本研究结果表明，底栖生物量的变化受到遮荫效应影响的浮游植物生物量，而这两个功能群之间的平衡可能会影响大底栖动物密度和生物量的变异性。
HitomiYamaguchi[a];ShigeruMontani[b];HiroakiTsutsumi[c];Ken-ichiroHamada[d][1];NaokoUeda[d][1];KuninaoTada[e];. Dynamics of microphytobenthic biomass in a coastal area of western Seto Inland Sea, Japan[J]. Estuarine, Coastal and Shelf Science, 2007,75(4): 423-432