The spatial and seasonal distributions of stable carbon and nitrogen isotopes (δ¹³C and δ¹⁵N) in dominant zooplankton groups were investigated in Jiaozhou Bay. Zooplankton δ¹³C values ranged from −22.89‰ to −15.86‰, and δ¹⁵N values ranged from 3.18‰ to 13.57‰, respectively. The δ¹³C and δ¹⁵N values generally followed the order of small zooplankton < large calanoids < small Sagitta < large Sagitta. Spatial distribution patterns of zooplankton δ¹³C and δ¹⁵N values varied in different seasons. Our results suggested that the spatial variation of δ¹³C was mainly controlled by terrigenous organic matter (OM) input and phytoplankton biomass, but water temperature may have played a key role in the seasonal variation of δ¹³C. In spring, the high phytoplankton biomass might increase the δ¹³C value of small zooplankton in the inner bay. During other seasons, the δ¹³C values of zooplankton generally increased from the inner bay to the outer bay, which might be associated with the influence of ¹³C-depleted terrigenous OM carried by the river discharge. Small zooplankton stable isotope values were significantly correlated with that of particulate organic matter (POM). The influence of anthropogenic nutrient input on isotopic baseline can be cascaded to the zooplankton, and the effect might be weak at higher trophic levels. The Bayesian standard ellipse areas of dominant zooplankton groups were generally smallest in the winter, suggesting a narrow niche width during that time. The niche partition between small zooplankton, large calanoids, and Sagitta was most distinct in winter, and followed by summer. The relative trophic level of Sagitta ranged from 2.23 to 4.01, which generally declined from the inner bay to the outer bay during the spring, autumn, and winter seasons. High anthropogenic nutrient loading might reduce the difference in trophic niches among zooplankton groups. This study provided detailed information on the distribution of zooplankton δ¹³C and δ¹⁵N in a coastal bay, which will be useful for understanding the anthropogenic influence on the ecosystem structure and function.

研究了胶州湾优势浮游动物群中稳定碳氮同位素（δ ¹³ C和δ ^{15 N）的空间和季节分布。}浮游动物δ ¹³ C值范围为-22.89‰至-15.86‰，δ ¹⁵ N值范围分别为3.18‰至13.57‰。δ ¹³ C 和 δ ¹⁵ N 值一般遵循小型浮游动物 < 大型 calanoids < 小型的顺序。射手座< 大射手座. ^{浮游动物δ 13} C和δ ¹⁵ N值在不同季节的空间分布格局不同。我们的研究结果表明，δ ¹³ C 的空间变化主要受陆源有机质（OM）输入和浮游植物生物量的控制，但水温可能在 δ ¹³ C 的季节变化中起关键作用。春季，高浮游植物生物量可能会增加内湾小型浮游动物的δ ^{13 C 值。}在其他季节，浮游动物的δ ¹³ C值普遍从内湾向外湾增加，这可能与¹³河流排放携带的耗尽碳的陆源有机质。小型浮游动物稳定同位素值与颗粒有机物（POM）显着相关。人为营养输入对同位素基线的影响可以级联到浮游动物，并且在较高的营养水平上影响可能较弱。优势浮游动物群的贝叶斯标准椭圆区域通常在冬季最小，表明在此期间生态位宽度较窄。小型浮游动物、大型有纲动物和射手座冬季最为明显，夏季次之。相对营养级射手座范围为2.23~4.01，春、秋、冬三季从内湾向外湾普遍下降。高人为营养负荷可能会减少浮游动物群之间营养生态位的差异。^{本研究提供了沿海海湾浮游动物δ 13} C和δ ¹⁵ N分布的详细信息，有助于了解人为对生态系统结构和功能的影响。