Warming and UV-B effects on phytoplankton communities in polar seas

本研究探讨了气候变暖和UV-B辐射增强这两个主要环境应激源对海洋浮游植物(微型藻类)群落的影响。我们将研究北极气温上升和冰盖减少对浮游植物细胞活力的影响，浮游植物的细胞活力可能会因环境中光照的快速增加而受到损害。我们还将通过在室外中隔层(装满当地海水的2立方米容器)中进行对照实验，测试变暖和增强的UV-B对南极洲和亚北极魁北克浮游植物的综合影响。在模拟局部臭氧消耗的增强UV-B或不增强UV-B的情况下，这些中温层中的许多将暴露在温度升高的环境中。由于温度升高应该有利于基于酶的修复机制，我们假设温度升高将有助于当地浮游植物群落(或更具抵抗力的藻类群)支持与极地环境变暖相关的辐射(包括紫外线辐射)的增加。我们还将从浮游植物群落组成和生物多样性的变化方面检查这些处理的结果，以评估气候变暖和UV-B如何改变海洋极地环境中营养食物网底部的群落。这些信息还将对卫星海洋颜色应用程序有用，目前正在开发卫星海洋颜色应用程序，以识别几个浮游植物组。

This research deals with the influence of climate warming and enhanced UV-B radiation, two major environmental stressors, on communities of marine phytoplankton (microscopic algae). We will examine the influence of increasing temperature in the Arctic, associated with reduced ice cover, on the cell viability of phytoplankton that may be harmed by the rapid increase in light in their environment. We will also test the combined influence of warming and enhanced UV-B on phytoplankton from Antarctica and in subarctic Quebec, by using controlled experiments in outdoors mesocosms (2 m3 containers filled with local seawater). A number of these mesocosms will be exposed to increased temperature with or without enhanced UV-B simulating local ozone depletion. Since increased temperature should favor enzyme-based repair mechanisms, we hypothesize that warmer temperatures will help local phytoplakton communities (or more resistant algal groups) support the increases in irradiances (including UV radiation) associated with warming in polar environments. We will also examine the outcome of these treatments in terms of changes in phytoplankton community composition and bio-diversity to assess how warming and UV-B are transforming the communities at the base of trophic food webs in marine polar environments. This information will also be useful for satellite ocean colour applications, which are being developed for identification of several phytoplankton groups.