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

本研究涉及气候变暖和增强的UV-B辐射这两个主要环境压力因素对海洋浮游植物（微型藻类）群落的影响。我们将研究北极温度升高的影响，与冰盖减少有关，对浮游植物的细胞活力可能会受到环境中光线迅速增加的伤害。我们还将通过在户外围隔生态系统（2立方米的容器装满当地海水）中进行受控实验，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。在有或没有增强的紫外线-B的情况下，一些中型生态系统将暴露在温度升高的环境中，模拟当地臭氧消耗。由于温度升高应该有利于酶为基础的修复机制，我们假设，温暖的温度将有助于当地的植菌群落（或更具抗性的藻类群体）支持与极地环境变暖相关的辐照度（包括紫外线辐射）的增加。我们还将研究这些治疗的结果在浮游植物群落组成和生物多样性的变化，以评估如何变暖和UV-B正在改变在海洋极地环境中的营养食物网的基础上的社区。这一信息还将有助于卫星海洋颜色应用，目前正在开发这种应用，以确定若干浮游植物群体。

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.