不同粒径和不同浓度清洁疏浚物对2种海洋微藻生长的影响

采用室内模拟试验研究了不同粒径和不同浓度悬浮清洁疏浚物对2种常见海洋微藻小球藻（Chlorella sp.）和新月菱形藻（Nitzschia closterium）生长的影响.结果表明,在8d的试验周期里,与对照组相比,不同浓度清洁疏浚物对2种海洋微藻生长的影响均达极显著水平（P＜0.01）.在相同粒径范围内,悬浮清洁疏浚物质量浓度为1～7g·L-1时,其对微藻生长的抑制作用随浓度升高而增加.随悬浮清洁疏浚物粒径的减小,2种海洋微藻的细胞密度呈下降趋势,＞88～ 125 μm粒径范围内生长的藻细胞受影响最小,0～16 μm粒径范围内生长的藻细胞受影响最大.悬浮清洁疏浚物对2种海洋微藻比生长速率的抑制作用明显,延缓了最大比生长速率出现的时间.2种海洋微藻对悬浮清洁疏浚物的敏感性存在差异,小球藻对悬浮清洁疏浚物的反应更加迅速.

Effects of Cleaning Dredged Material on Growth of Two Species of Marine Microalgae as Affected by Its Particle Size and Concentration.

A simulation test was carried out in laboratory to study effects of cleaning dredged material on growth of two species of marine microalgae （Chlorella sp.and Nitzschia closterium） as affected by its particle size and concentration.Results show that after 8 days of incubation,the effect of the materials on growth of the two species of marine microalgae was very significant regardless of their concentration （P〈0.01）.In the case that the suspended cleaning dredged materials were in the same range of particle size,but varied in concentration in the range of 1-7 g · L-1,the effect of inhibiting growth of the microalgae intensified with the rising concentration.With the suspended cleaning dredged materials declining in particle size,the two species of marine microalgae showed a downward trend in cell density.The effect was the least when the material was in the range of 〉88-125μm in particle size,and the greatest when the material in the range of 0-16 μm in particle size.The suspended cleaning dredged materials inhibited the growth rates of the two species of marine microalgae significantly,delaying the appearance of the maximum specific growth rate.Two species of marine microalgae were different in sensitivity to the suspended cleaning dredged materials.Chlorella sp.was more sensitive,which may be attributed to their difference in cell structure,physiological property and ecological habit.