GLOBEC 2000: Long-term Changes in California Current Zooplankton Assemblages and Euphausiid Population Dynamic Parameters

PI将测试GLOBEC核心假设，即阿拉斯加沿海海湾和加利福尼亚海流系统的生产机制是协变的，并通过大气和海洋强迫耦合，通过比较分析浮游动物种群和东北太平洋不同地区的大气和海洋强迫措施。在第一阶段的研究中，PI发现了加州海流浮游动物（区域I）在年代际时间尺度上的实质性变化（例如，salp和磷虾类的变化）以及年际时间尺度（例如，与厄尔尼诺有关的桡足类多样性和浮游动物生物量的变化）。对于第2阶段，PI将重点关注CCS中部/北方加州外海的第二区域，以确定他们检测到的明显扰动在CCS不同区域是否具有空间连贯性，并与东北太平洋其他地方的浮游动物波动有关，特别是俄勒冈州外海和阿拉斯加湾沿岸。 此外，估计瞬时，特定阶段的死亡率为磷虾种群的东北太平洋将使用脂褐素为基础的措施磷虾年龄和逆建模技术。还将利用浮游动物稳定同位素研究食物网结构的长期稳定性。

The PIs will test the GLOBEC core hypothesis that production regimes in the Coastal Gulf of Alaska and Califomia Current System covary, and are coupled through atmospheric and oceanic forcing, through comparative analysis of zooplankton populations and measures of atmospheric and oceanic forcing in different regions of the NE Pacific. During a Phase 1 study, the PIs uncovered substantial changes in the California Current zooplankton (Region I) on interdecadal time scales (e.g., changes in salp and euphausiid regimes) as well as interannual time scales (e.g., El Nino-related changes in copepod diversity and zooplankton biomass). For Phase 2 , the PIs will focus on Region II of the CCS off central/northern California to determine whether the pronounced perturbations that they detected are spatially coherent in different regions of the CCS and are linked to zooplankton fluctuations elsewhere in the NE Pacific, specifically off Oregon and in the Coastal Gulf of Alaska. In addition, estimates of instantaneous, stage-specific mortality rates for euphausiid populations of the NE Pacific will be made using lipofuscin-based measures of euphausiid age and inverse modeling techniques. Long-term stability in food web structure also will be investigated using zooplankton stable isotopes.