应用同位素分析黑龙江中游主要鱼类营养层次

2010年5月—2011年10月对黑龙江中游采集的32种鱼类和6种底栖无脊椎动物,运用稳定碳、氮同位素方法进行水生态营养层次的分析。结果显示,鱼类δ13C值为-32.00‰～-17.32‰,相差14.68‰;δ15N值为7.58‰～14.78‰,差值达6.80‰,跨度都很大。底栖无脊椎动物δ13C值和δ15N值的跨度不大,δ13C值为-29.64‰～-26.10‰,相差3.54‰;δ15N值为7.09‰～9.91‰,相差2.82‰。通过δ15N值计算出黑龙江中游32种主要鱼类和6种底栖无脊椎动物食物网营养层次,其中肉食性鱼类鳇(Huso dauricus)占据了黑龙江中游鱼类中最高的营养位置。通过分析初步建立了水体食物网连续营养谱,并结合底栖无脊椎动物同位素数据勾勒出黑龙江中游食物网营养结构图。

Study on trophic level of main fishes in the middle reach of Heilongjiang River by stable carbon and nitrogen isotopes analysis

The trophic ecology of the middle reach of Heilongjiang River was analyzed by using of stable isotopes analysis,especially carbon and nitrogen from May 2010 to October 2011.Sampled 32 fish species and 6 benthonic invertebrates were used to analyze the trophic ecology of Heilongjiang River.There was significant variation in the δ13 C and δ15N values of fishes.δ13 C ranged from-32.00‰ to-17.32‰ and the phase contrast was 14.68‰,while δ15N ranged from 7.58‰ to 14.78‰,and the phase contrast was 6.80‰.The variation in the δ13 C and δ15N values of benthonic invertebrates was smaller.δ13 C ranged from-29.64‰ to-26.10‰ and the phase contrast was 3.54‰,while δ15N ranged from 7.09‰~9.91‰,and the phase contrast was 2.82‰.The trophic level of 32 fish species and 6 benthonic invertebrates were estimated based on the δ15N values,among which carnivores Huso dauricus seized the supreme trophic level.The continuous nutrition spectra of waters of food web in the middle reach of Heilongjiang River were initially constructed and the tropic structure chart of ecosystem was outlined combined with the isotopes value of benthonic invertebrates.