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Daily estimates reveal fine-scale temporal and spatial variation in fish survival across a stream network

August 6, 2020

Environmental drivers of population vital rates, such as temperature and precipitation, often vary at short time scales, and these fluctuations can have important impacts on population dynamics. However, relationships between survival and environmental conditions are typically modeled at coarse temporal scales, ignoring the role of daily environmental variation in survival. Our goal was to determine the importance of fine-scale temporal variation in survival to population dynamics of stream salmonids. We extended the Cormack–Jolly–Seber model to estimate daily survival rates from seasonal samples of individually marked brook trout (Salvelinus fontinalis) in a stream network. Daily variation in temperature and flow were strongly associated with survival, but relationships varied between juvenile and adult trout and among streams. In all streams, juveniles had higher mortality in warm, low-flow conditions, but in the two larger streams, cold, high-flow conditions also reduced juvenile survival. Adult survival decreased during low flows, particularly in the fall spawning period. Differing survival responses among stream network components to short-term environmental events created shifts in optimal location for maximum survival across life stages, seasons, and years.

Citation Information

Publication Year 2019
Title Daily estimates reveal fine-scale temporal and spatial variation in fish survival across a stream network
DOI 10.1139/cjfas-2018-0191
Authors Evan S. Childress, Keith Nislow, Andrew R. Whiteley, Matthew O'Donnell, Benjamin Letcher
Publication Type Article
Publication Subtype Journal Article
Series Title Canadian Journal of Fisheries and Aquatic Sciences
Index ID 70211648
Record Source USGS Publications Warehouse
USGS Organization Leetown Science Center