15N isotope fractionation in an aquatic food chain： Bellamya aeruginosa （Reeve） as an algal control agent

• Published in: Journal of environmental sciences (China) 2010 (2), p.242-247
• Main Author: Shiqun Han Shaohua Yan Kaining Chen Zhenhua Zhang Rengel Zed Jianqiu Zhang Wei Song Haiqin Liu
• Format: Article
• Language: English
• Subjects: 同位素分馏; 同位素示踪技术; 控制剂; 氮同位素; 藻类生物量; 铜锈环棱螺; 食物链
• ISSN: 1001-0742; 1878-7320

^ 15N isotope tracer techniques and ecological modeling were adopted to investigate the fractionation of nitrogen, its uptake and transformation in algae and snail （Bellamya aeruginosa Reeve）. Different algal species were found to differ in their uptake of nitrogen isotopes. Microcystis aeruginisa Ktitz. demonstrated the greatest ^15N accumulation capacity, with the natural variation in isotopic ratio （δ^15N） and the isotope fractionation factor （ε,‰） being the highest among the species investigated. The transformation and utilization of ^15N by snails differed depending on the specific algae consumed （highest for Chlorella pyrenoidosa Chick., lowest for M. aeruginisa）. When snails was seeded in the experimental pond, the algae population structure changed significantly, and total algal biomass as well as the concentration of all nitrogen species decreased, causing an increase in water transparency. A model, incorporating several chemical and biological parameters, was developed to predict algal biomass in an aquatic system when snails was present. The data collected during this investigation indicated that the gastropods such as snails could significantly impact biological community and water quality of small water bodies, suggesting a role for biological control of noxious algal blooms associated with eutrophication.