富营养化水体中磷限制对浮游甲壳动物摄食效率的影响及其生态学效应研究

The phosphorus limitation in aquatic food chain would result in the change of crustacean zooplankton biomass and community structure in eutrophic water body. In eutrophic water body, the morality、 the somatic growth rate (SGR) and the reproduction of crustacean zooplankton was stressed by the dietary phosphorus, and lead to a reduction of the grazing rate and the control of algae biomass. Body alkaline phosphatase activity (APA) was detected as an indicator of dietary phosphorus (P) stress in Daphnia. An ecological investigation on the effects of Phosphorus loading in the source, the gallery and the pool to the crustacean zooplankton community was operated in an eutrophic river basin. An article aquatic food web (AAFW) system was developed at the source of the eutrophic river. The P-content of seston, the growth rate, the body APA and the body P-content of Daphnia magna were detected in the AAFW system. Our research give a comprehension on the "P limitation" of Daphnia in the eutrophic water body. The relationship between the P-content of seston and the grazing rate、the APA of Daphnia magna were analyzed in the present study. The P distribution in the aquatic food web was also researched for the explaination of P-limitation. Our researches would give an a theoretical support to the control of algae bloom and the reduction of nutrients by typical biomanipulation in eutrophic water body.

富营养化水体中的浮游甲壳动物会因食物链中的磷限制作用而发生生物量下降和群落结构的改变。藻类食物中的磷含量与浮游甲壳动物的个体死亡率、体长生长速率及繁殖能力密切相关，并由此造成其磷吸收效率和控藻能力的改变。浮游甲壳动物的碱性磷酸酶活性（APA）可以标记其在摄食过程中受到的磷限制。本项目拟通过富营养化水体磷负荷与浮游甲壳动物群落结构、AAFW(人工水生食物网) 系统中藻类C：P比与浮游甲壳动物滤食率、浮游甲壳动物磷含量与摄食藻类生物量及浮游甲壳动物体内碱性磷酸酶活性（APA）与藻类食物中磷含量之间关系的研究来分析水生食物链中的磷限制对浮游甲壳动物的生理学和生态学影响，揭示磷在水生食物网中的的分布策略和对浮游甲壳动物的限制作用。为富营养化水体的磷消减和藻类控制提供科学依据。

磷(Phosphorus)是构成水生生物细胞和组织必不可缺的元素, 也是造成水体富营养化和藻类水华的重要原因。富营养化水体中浮游甲壳动物对水体中磷的吸收、储存和转运会影响水生食物链的结构，进而影响到水体中的营养盐消减和藻类水华控制。本项目通过分析富营养化水体磷负荷与浮游甲壳动物群落结构之间的联系;构建AAFW(人工水生食物网) 系统消减农业面源污染的氮磷营养盐和控制藻类水华;藻类C：P比与浮游甲壳动物滤食率研究来分析水生食物链中的磷限制对浮游甲壳动物的生理学和生态学影响。研究发现，富营养化水体中的浮游甲壳动物丰度和体型受水体中的总磷(TP)和氮磷比（TN/TP）的影响显著。 AAFW(人工水生食物网) 系统具有较强的消减营养盐和控制藻类水华的能力。其中，大型浮游甲壳动物-蚤状溞（Daphnia pulex）通过摄食大量吸收水体中的磷并储存于体内，有效的消减了水体中的生物可利用性磷, 实现了藻类水华的控制和水质净化。室内研究中发现大型浮游甲壳动物的个体死亡率、体长生长速率及繁殖能力与藻类食物中的磷含量密切相关。研究揭示了磷在水生食物网中的的分布策略和影响浮游甲壳动物摄食作用的内在机制，为富营养化水体的磷消减和藻类控制提供了科学依据。