A CLIMATE‐BASED INDEX OF HISTORIC SPAWNING‐STREAM HYDROLOGY

摘要: Reproductive success of stream-spawning Oncorhynchus fishes (Pacific salmon, rainbow trout, cutthroat trout and their allies) may be greatly affected by stream discharge or its covariate, temperature, during the spawning season. Because such data for physical environment not have been routinely collected as part previous investigations these fishes, identification simple but robust indices historic, seasonal using long-term climate sets, would important, especially to historic population dynamics. This study examined statistical associations among several variables spawning-season (approximately June) discharges temperatures Clear Creek, a Yellowstone Lake tributary used clarkii bouvieri (YCT), from lake. Correlation analysis showed that total water-year degree-days (calculated on basis mean daily air temperature > 0°C) at Village, lake's north shore, was index (both negative positive, respectively) consecutive, semi-month metrics creek temperature YCT (and subsequent use Village degree days metric an environmental variable in dynamic, age-structured model lacustrine–adfluvial Creek) how exploratory analyses fragmentary regionally unique sets Creek revealed variation important understanding dynamics Creek's population, which is key stock Lake. In addition, extensive variables, along with temporal trends two broadly varied across region past decades. Those observations implications hydrology all tributaries YCT. Copyright © 2011 John Wiley & Sons, Ltd.