石油烃和营养盐的复合污染对海洋浮游植物的影响Ⅱ.营养盐对浮游植物吸收石油烃的影响

THE COMBINED EFFECT OF NUTRIENTS AND PETROLEUM HYDROCARBON ON PHYTOPLANKTONⅡ.THE EFFECTS OF NUTRIENTS ON THE UPTAKE OF PETROLEUM HYDROCARBON BY PHYTOPLANKTON

通过向培养体系中添加不同浓度的营养盐和相同浓度的石油烃,对中肋骨条藻(Skeletonema costatum)、赤潮异弯藻(Heterosigma akashiwo Hada)和锥状斯氏藻(Scrippsiella trochoidea)进行周期性培养,研究了营养盐对海洋微藻的石油烃吸收动力学的影响。当营养盐按照Redfield比值添加时,三种微藻在初始的12h中摄取的石油烃都是最大的。对于三种藻而言,不同营养盐浓度条件下,对石油烃的摄取程度从强到弱依次为氮潜在限制>磷潜在限制>硅潜在限制(中肋骨条藻)。在相同营养盐浓度条件下,在这三种微藻中,中肋骨条藻对石油烃的摄取程度最大,在初始的12h里,石油烃浓度的减少几乎完全是藻将摄取的吸附在表面或吸收入体内的石油烃又重新释放回了水体引起的。

Skeletonema costatum, Heterosigma akashiwo, and Scrippsiella trochoidea were cultivated in the medium added with petroleum hydrocarbon and nutrients. The effects of nutrients on the uptake of petroleum hydrocarbon by phytoplankton were studied. Within the first 12 hours, when the nutrients were added according to the Redfield ratio, the uptake of petroleum hydrocarbon by the three phytoplanktons was the best. When nutrients concentration were in other ratios, the uptake order of petroleum hydrocarbon by phytoplanktons in the first 12 hours was N potential limitation 〉 P potential limitation 〉 Si potential limitation （only for S. costatum）. Under the same nutrient conditions, S. costatum had the most uptake of petroleum hydrocarbon. In the first 12 hours, the decrease of concentration of petroleum hydrocarbon by the uptake of phytoplankton was quick. After 12 hours, the concentration of petroleum hydrocarbon in solution began to increase because the petroleum hydrocarbon was released from phytoplankton previously adsorbed.