Critical thermal refugia for Atlantic salmon and brook trout populations of eastern Canadian rivers

该项目涉及8名具有一系列生物和水文专业知识的大学研究人员。目的是研究在魁北克南部和新不伦瑞克省沿河流的局部冷水避难所鲑鱼的物理控制和生物学意义。在21世纪夏季变暖的情况下，这样的热避难所可能会成为关键，限制我们主要的冷水运动鱼类，鲑鱼和溪鳟在其种群范围的南部极限的生存栖息地。冷热避难所既不均匀又不明显：它们在尺寸、空间分布和物理控制方面范围广泛：一些与地下水沿河床上涌有关，另一些与特定支流的河口有关，还有一些与小的潜流渗漏有关。沿着鲑鱼或鳟鱼河流系统的这些隐蔽栖息地之间的典型分离鲜为人知，鲑鱼探测和迁移到这些地方很远的能力，或鱼类死亡率作为距离和温度模式的函数。此外，在21世纪后期可能的温度、降雨和积雪条件下，主要类型的河内地下水上升流作为热避难所的相对尺度和价值也不清楚。本项目将采用热红外探测与鱼类生态实地调查相结合的方法，研究这些生境的空间分布和支持能力。一般水文地质模型将在区域气候情景的背景下探索一系列的流内地下水上升流设置。我们的工业合作伙伴Hydro-Quebec需要我们最先进的工具和模型来监测和预测河流流量变化（和深层水库释放）对鱼类栖息地（包括热避难所）和河流生态系统的影响。在适应气候变化的北方河流生态系统管理和优化未来鱼类保护投资方面，加拿大可以预期广泛的环境效益，通过澄清未来的热制度在多大程度上限制单个河流中冷水物种的生产力或生存，作为其特定避难所空间分布的功能。

This project involves 8 university researchers with a range of biological and hydrological expertises. It aims to study the physical controls and biological significance for salmonids of localized, cool water refugia sites along rivers in southern Quebec and New Brunswick. Under a 21st century regime of warming summers, such thermal refugia may become key, limiting habitats for the survival of our dominant cold water sport fish, salmon and brook trout, at the southern limits of their population range. Cool thermal refugia are both heterogeneous and visually inconspicuous: they range widely in dimensions, spatial distribution and physical controls: some are associated with groundwater upwellings along river beds, others with the mouths of particular tributaries and some, with small hyporheic seeps. The typical separation between these cryptic habitats along salmon or trout rivers systems is poorly known as is the ability of salmonids to detect and migrate significant distances to such sites, or fish mortality rates as a function of distances and temperature patterns. Moreover, under likely scenarios of future temperature, rainfall and snow cover conditions for the later 21st century, the relative dimensions and value as thermal refugia of major types of in-stream groundwater upwellings is also unclear. This project will apply thermal IR detection combined with fish ecology field surveys to study the spatial distribution and support capacity of these habitats. Generic hydrogeological models will explore a range of in-stream groundwater upwelling settings in context of regional climate scenarios. Our industrial partner Hydro-Quebec needs our state of the art tools and models to monitor and predict effects of river flow modifications (and deep reservoir releases) on fish habitats (including thermal refugia) on the river ecosystems they impact. Broad environmental benefits for Canada can be expected in terms of adaptations to climate change of Boreal river ecosystem management and optimisation of future fish conservation investments, by clarifying to what extent future thermal regimes can limit the productivity or the survival of cold water species in individual rivers, as a function of its particular refugia spatial distribution.