Nutrient bioavailability and primary production in Lake Simcoe

该申请将支持的研究项目是对西姆科湖养分生物利用度和初级生产的研究。西姆科湖是安大略省最大的内陆湖，也是加拿大的冰钓之都。它也是8个城市的饮用水来源，并受到营养投入增加的威胁。迄今为止，Simcoe湖的初级生产从未被测量过，也没有对微生物食物网进行评估。藻类或浮游植物构成了湖泊食物网的基础，了解它们的初级产量将决定湖泊中可能的鱼类产量。本研究计划的主要目的是确定Simcoe湖浮游植物群落的限制性营养物质和初级生产的差异。这是通过对微生物生物量、生理和代谢进行全面的、全年的检查来评估的。如果我们能够了解是什么控制了C的循环，也许我们可以预测和缓解季节性缺氧，恢复西姆科湖的冷水渔业。现有HQP人员7人，其中博士后1人，硕士生2人，本科暑期生2人，技术人员2人。此申请是为拟议的研究所需的四个独立设备。YSI Sonde是一种用于分析湖泊水柱的现场仪器，之所以选择它，是因为它可以在Simcoe这样的大型湖泊中使用，在恶劣的天气条件下需要深入分析。水PAM是一种专门的荧光计，用于评估水中浮游植物群落的可变荧光，并用于检查浮游植物生理学和提供产量估计数。同位素分析仪是一种专门的、廉价的、高效的测量稳定同位素的工具。分光光度计将用于测量水中溶解的营养物浓度。

The research program that this application will support is the examination of nutrient bioavailability and primary production in Lake Simcoe. Lake Simcoe is the largest inland lake in Ontario and the ice-fishing capital of Canada. It is also the source of drinking water to 8 municipalities and is under the threat of increased nutrient inputs. To date, primary production has never been measured on Lake Simcoe, and there has been no assessment of the microbial food web. Algae, or phytoplankton, form the base of the food web in lakes and understanding their primary production will determine the possible fish production in the lake. The main objective of this research program is to determine the limiting nutrient(s) to the phytoplankton communities in Lake Simcoe and the differences in primary production. This is being assessed with a thorough, year-round examination of microbial biomass, physiology and metabolism. If we can understand what controls the cycling of C, perhaps we can predict and mitigate the seasonal hypoxia and restore the cold-water fisheries to Lake Simcoe. This program currently involves 7 highly qualified personnel (HQP) including a postdoctoral fellow, 2 masters students, 2 undergraduate summer students and 2 technicians. This application is for four independent pieces of equipment required for the proposed research. The YSI Sonde is a field instrument used to profile the water column of lakes and it was selected due to its use in large lakes such as Simcoe where profiling is needed to deep depths under adverse weather conditions. The Water PAM is a specialized fluorometer used to assess the variable fluorescence of phytoplankton communities in water and is used to examine phytoplankton physiology and provide estimates of production. The isotope analyzer is a specialized, inexpensive and efficient tool to measure stable isotopes. The spectrophotometer will be used to measure dissolved nutrient concentrations in water.