基于稳定同位素方法的东海北部及其邻近水域主要游泳动物营养结构变化

Variation in trophic structure of nekton organisms from the northern East China Sea and adjacent waters based on stable isotope values

依据2009年夏季和2010年春季东海北部及其邻近水域的底拖网渔业资源调查样品,利用稳定同位素生态位的方法分析该海域内主要游泳动物营养结构的季节变化,并根据δ^(13)C-δ^(15)N的二维坐标计算了6个营养结构的量化指标。结果表明,东海北部及其邻近水域主要游泳动物的δ^(13)C值存在显著的季节差异(P<0.05),δ^(15)N值无显著差异(P>0.05);稳定同位素的量化指标结果表明,游泳动物群落的营养结构存在季节差异,与2009年夏季相比,2010年春季的δ^(15)N比值范围(NR)、δ^(13)C比值范围(CR)、面积(TA)、平均离心距离(CD)均有所升高,而最邻近距离平均值(NND)、最邻近距离标准差(SDNND)值相对持平或略有下降。本研究结果表明,东海北部及其邻近水域主要游泳动物营养结构的季节差异与群落内食源多样性水平和营养冗余程度的变化密切相关。

Based on materials collected from large-scale surveys in the northern East China Sea and adjacent waters in the summer of 2009 and the spring of 2010 （29° - 34°N, 122° - 127°E） ,the paper studied seasonal variations of the trophic structure of nekton organisms through analysis of stable isotopic contents. The isotopic niche defined as a position in the δ13C-δ15N planar was applied, and six quantitative metrics （ratio range of δ15 N, NR ; ratio range of δ13 C, CR ; area, TA ; average distance of centroid, CD; the minimum mean, NND; the minimum standard deviation, SDNND） based on stable isotopic were calculated to show the trophic structure characteristics. The results showed that there were significant differences between δ13C values of samples collected in two seasons, while no significant difference between δ15N values was found. Trophic structure of nektons differed remarkably in the two sampling seasons inferred from six quantitative metrics. NR, CR, TA and CD were much higher in the spring of 2010 than those in the summer of 2009, while NND and SDNND were lower in the spring than those in the summer. The characteristics of data in this study demonstrates that there are high diversity of food resources and trophic redundancy in the nekton community in the northern East China Sea and adjacent waters.