菲律宾蛤仔(Ruditapes philippinarum)对潮间带水层-沉积物界面颗粒通量影响的研究

Effects of Manila Clam (Ruditapes philippi narum) on the Benthic-Pelagic Particle Flux in Xuejiadao Intertidal Zone

研究利用中型生物扰动系统 (AFS)对胶州湾薛家岛潮间带菲律宾蛤仔 (Ruditapesphilippinarum)养殖断面和非养殖断面的中潮和低潮 4个站位的生物沉降和沉积物的再悬浮过程进行测定。结果表明生物沉降作用与大型滤食性双壳类动物 -菲律宾蛤仔的丰度呈显著的正相关关系 (r=0 .984 ,P<0 .0 5 ) ,养殖断面的生物沉降作用要明显地大于非养殖断面。在菲律宾蛤仔的低密度区 ,生物沉降的作用小于自然沉降 ,而在其养殖的高密度区 ,生物沉降率约为自然沉降率的4倍。薛家岛潮间带沉积物的临界侵蚀速率为 17.4～ 2 0 .4 cm/ s。沉积物的稳定性与所测生物因子的关系不密切 (P>0 .0 5 )。作者推测两个断面中潮站位沉积物的相对易侵蚀性 。

An annular flux system (AFS) was deployed to measure t he biodeposition and the sediment resuspension processes at four stations in the mid-shore and low-shore along both natural and Manila clam (Ruditapes phili ppinarum) farming transects in Xuejiadao intertidal zone. The results showed t hat there was a significant correlation between the biodeposition rates and the density (r = 0.984, P<0.05) of the filter feeder, Manila clam. The effect of bio deposition at the farming transect was more intensive than that at the natural t ransect where the biodeposition effect was lower than that resulting from natura l sedimentation. In contrast, the biodeposition rate at the culture site with th e high density of Manila clams was four times of the natural sedimentation rate. The critical erosion velocities of intertidal sediments at Xuejiadao were from 17.4 to 20.4cm s -1 . It was found that the site differences in sediment erodibility were not significantly correlated with measured biota factors such as total macrofauna biomass, total abundance and macrofauna densities (P>0.05). It was supposed that the lower stability of sediments in the mid-shore level at both transects was probably associated with higher densities of bioturbators an d with disturbance by shrimp farming in the high-shore.