Environmental forcing of primary production in the changing Arctic and sub-arctic seas

北海正在发生的蜕变为我们提供了一个自然实验，必须利用它来揭示多种环境压力因素对海洋初级生产（PP）和生物地球化学通量的影响。特别是在北极，PP对自然和人为强迫（冰盖、光照、营养物和温度）的响应以及随之而来的对气候的反馈（如温室气体的释放或捕获）存在很大的不确定性和争议。未来5年的研究目标是：(1)阐明PP的物理驱动因素；(2)量化氮循环中强烈影响PP的生物步骤；(3)研究北极/亚北极在养分负荷和淡水输送方面的连通性。假设将通过自主观察（系泊）、文化工作、历史数据和基于船舶的过程研究相结合进行测试。后者将依靠最先进的技术，使用稳定同位素作为原位（自然丰度）碳和氮通量的示踪剂，并在15N/ 13c标记的底物的实验孵育期间。随着全球渔业持续减少，北部水道变得更加安全，新的北极资源的价值可能会飙升。我的研究将根据可再生资源PP的数量和质量来评估北海的承载能力。对基本的一级生态过程及其对多种环境压力的响应的定量理解将增加和改进约束未来情景的数值模型。新的知识应使加拿大的管理人员、决策者和工业界能够更好地评估、预测和适应不断变化的冰逃逸及其对生态系统健康和服务的影响。对加拿大人的其他好处包括更好地掌握海洋生态系统和远北与大西洋各省沿海水域之间的关键联系，以及培训下一代生物海洋学家。

The ongoing metamorphosis of northern seas hands us a natural experiment that must be tapped to unravel the effects of multiple environmental stressors on marine primary production (PP) and biogeochemical fluxes. For the Arctic in particular, the response of PP to natural and anthropogenic forcing (ice cover, light, nutrients & temperature) and the ensuing feedbacks on climate (e.g. release or capture of greenhouse gases) are subject to large uncertainties and debate. Research objectives for the next 5 years are to (1) elucidate the physical drivers of PP, (2) quantify biological steps of the nitrogen cycle that strongly affect PP, and (3) investigate Arctic/sub-Arctic connectivity with respect to nutrient loading and freshwater deliveries. Hypotheses will be tested with a combination of autonomous observation (moorings), culture work, historical data and ship-based process studies. The latter will rely on state-of-the-art techniques that use stable isotopes as tracers of carbon and nitrogen fluxes in situ (natural abundance) and during experimental incubations with 15N/13C-labeled substrates. As global fisheries continue to decline and northern waterways become safer, the value of new arctic resources is likely to soar. My research will assess the carrying capacity of northern seas in terms of the quantity and quality of the PP available to renewable resources. Quantitative understanding of fundamental, first-order ecological processes and their response to multiple environmental stressors will increase and improve the numerical models that constrain future scenarios. The new knowledge should empower Canadian managers, policy makers and industry with better means to evaluate, anticipate and adapt to the changing icescape and its impacts on ecosystem health and services. Other benefits to Canadians include a better grasp of marine ecosystems and crucial linkages between the far north and the coastal waters of Atlantic Provinces, as well as training of the next generation of biological oceanographers.