Exploring the sources, sinks and uptake of carbon and nitrogen in the coastal ocean

海洋在加拿大的经济和文化中扮演着重要的角色。大气温度的上升、天气模式的变化和人类活动的变化正在推动陆地上的变化，这些变化直接影响到海洋生态系统的化学和生产力。被称为浮游植物的光合作用微生物构成了海洋食物网的基础，对从大气中隔离二氧化碳至关重要。碳和氮等元素是地球上所有生命的关键组成部分，它们的浓度和组成的变化可能会促进或抑制浮游植物的生长，从而抑制海洋生产力。浮游植物种类、丰度和生长速度的变化也会对水生食物网、生物地球化学通量和气候反馈产生重大影响。因此，研究将导致更深入地理解当前的流程并增强对未来生产率的预测能力是至关重要的。 通过将现场生态系统观测与明确的实验相结合，拟议的研究计划将揭示关键环境变化变量、元素循环和海洋生产力之间的联系。该计划将通过确定影响浮游植物和细菌利用不同碳源和氮源能力的因素和阈值，调查气候变化、微生物生理变化和人类直接影响(通过工业和土地利用的变化)对浮游植物和细菌生长的影响。具体地说，它将评估现有和新兴微生物的生理能力，确定陆上化学投入的构成，确定水化学变化风险最大的地区，并确定将实现最佳长期生态和经济效益的渐进式改善。这将使人们能够从根本上了解对预测未来海洋生态系统的变化至关重要，并将上游变化与其下游后果联系起来。 气候和生态系统模型师、行业、管理和政府机构将对研究结果感兴趣。对模型界的贡献将是准确的生态系统模型所需的碳和氮利用、固定和再生率测量，这些模型能够预测环境变化对海洋生产力和全球元素循环的影响。这项研究将通过它与不断扩大的水产养殖业的联系来为经济做出贡献。从长远来看，知道在哪里不应该建立水产养殖设施将有助于种植者提高生产率。这项工作还将通过确定和优先考虑今后需要减少或调停以维持和改善生态系统健康和生产力的关键的自然和人为化学投入，为管理决策提供信息。

The ocean plays an important role in the economy and culture of Canada. Rising atmospheric temperatures, changing weather patterns, and alterations in human activities are fueling changes on land that directly impact the chemistry and productivity of ocean ecosystems. Photosynthetic microorganisms called phytoplankton form the base of the ocean food web and are critical to the sequestration of carbon dioxide from the atmosphere. Shifts in the concentration and composition of elements like carbon and nitrogen, key components of all life on earth, can promote or inhibit phytoplankton growth and thus ocean productivity. Variations in the types of phytoplankton, their abundance and how fast they grow can also have substantial ramifications for aquatic food webs, biogeochemical fluxes, and climate feedbacks. Therefore, research that will lead to a deeper understanding of current processes and enhanced predictive capabilities of future productivity is paramount. By coupling in situ ecosystem observations with explicit experimentation the proposed research program will uncover linkages between key environmental change variables, elemental cycles and ocean productivity. This program will investigate the impacts of climate change, variations in microbial physiology and direct human influence (via changes in industry and land-use) on phytoplankton and bacterial growth by identifying the factors and thresholds that impact their ability to use different carbon and nitrogen sources. Specifically, it will assess the physiological capabilities of existent and emergent microorganisms, characterize the composition of land-based chemical inputs, identify regions most at risk to changes in water chemistry, and determine incremental improvements that will achieve the best long-term ecological and economic benefits. This will enable a fundamental understanding critical to predicting future changes in marine ecosystems and connect upstream changes to their down-stream consequences. The results will be of interest to climate and ecosystem modelers, industries, and management and governmental agencies. The contribution to the modeling community will be carbon and nitrogen utilization, fixation and regeneration rate measurements required for accurate ecosystem models capable of predicting environmental change effects on ocean productivity and global elemental cycles. This research will contribute economically through its connection to the expanding aquaculture industry. Knowing where not to establish an aquaculture facility will help growers be more productive over the long term. This work will also serve to inform management decisions by identifying and prioritizing critical natural and anthropogenic chemical inputs that need to be reduced or mediated in the future to maintain and improve ecosystem health and productivity.