Studies on the trophic structure of fish in Sanjiao Lake based on carbon and nitrogen stable isotope analysis
With the intensification of urbanization, lake pollution prevention and ecological protection are fa-cing severe challenges.The δ13C value and δ15N value composition, trophic level and food network structure characteristics of fish and their seasonal variation patterns were analyzed by carbon and nitrogen stability isotope technology to understand the characteristics of the trophic structure of the ecosystem of the Sanjiao Lake in Wu-han.The results showed that the mean values of δ13C and δ15N in Sanjiao Lake were -26.16‰±1.33‰ and 13.19‰ ±1.97‰.There were no significant seasonal differences in δ13C value, δ15N values were significantly different in autumn 11.33‰±2.02‰ from summer 13.67‰±1.24‰ and winter 14.46‰±1.36‰.The δ15N value of fish in Sanjiao Lake was relatively high 6.48‰～16.41‰, which was higher than that of some lakes with less eutrophication.The average trophic level of fish in the Sanjiao Lake was 3.05±0.64, and there were significant differences in the trophic level of fish in different seasons, with the largest in winter(3.48±0.39) and the lowest in autumn(2.45±0.57).There were also differences in the nutritional level of different feeding fish,with the average trophic level of carnivorous fish being the highest and plankton-eating fish being the low-est.There were seasonal differences in the nutritional structure of the fish community in the Sanjiao Lake.The basic food source(CR), trophic level(NR), total niche space(TA) and core niche space(SEAc) of fish in autumn were the largest, indicating that the diversity of fish food sources in autumn was high.The values of NR,TA, and SEAc in spring were the smallest, indicating that fish food sources were scarce and that there was competition between fish.There were many omnivorous fish and few carnivorous fish in the Sanjiao Lake.It is recommended that the fish community be regulated by adding some plankton-eating fish and carnivorous fish.In addition,hat submerged plants be planted to restore fish habitats.
万方数据
维普
