Kimmel William G, Argent David G, Kimmel David G
Department of Biology, Earth and Environmental Sciences, PennWest - California 250 University Avenue, California, PA, 15419, USA.
23421 8TH PL W, Bothell, WA, 98021, USA.
Environ Manage. 2025 Jul;75(7):1859-1871. doi: 10.1007/s00267-025-02198-y. Epub 2025 Jun 6.
A warming climate has been widely recognized as an existential threat to populations of Eastern Brook Trout (Salvelinus fontinalis) inhabiting headwater streams spanning the Appalachian Mountains. However, little information is available on the status of individual streams at fine-scale geographic levels. To address this issue, we evaluated air and in-stream temperature time-series over a seven-year period among 10 streams on Laurel Hill in southwestern Pennsylvania. Thermal sensitivity (E, the slope of the air-instream temperature relationship) was calculated for each stream during the Brook Trout growth seasons (April-September) to determine potential effects on resident fish. Values of E varied interannually within and among streams in terms of annual maximum growth season temperatures, days of Brook Trout thermal stress (>18 °C), and estimated number of days to hatch. A value of E approximating 0.42 served as an inflection point above which periods of thermal stress rose sharply. E was also positively related to estimated days to hatch. Overall, the data from this study document differing responses to warming from streams as close as 2 km apart, suggesting a need for conservation measures at a local level. The use of paired in-stream and riparian temperature data loggers provides an inexpensive way to identify and to monitor streams that may be particularly vulnerable to warming. Data from this study indicated that warming has detrimental implications for resident eastern Brook Trout and, without consideration of groundwater and riparian canopy protection, along with revised stocking paradigms, continuing existential impacts can be expected. Identifying which streams are most susceptible to warming impacts on Brook Trout using a simple metric, such as thermal sensitivity, will allow for more targeted conservation efforts by fishery/watershed managers to protect this at-risk native species.
气候变暖已被广泛认为是对栖息在横跨阿巴拉契亚山脉源头溪流中的东部溪鳟（Salvelinus fontinalis）种群的生存威胁。然而，在精细地理尺度上，关于各个溪流状况的信息却很少。为解决这一问题，我们评估了宾夕法尼亚州西南部劳雷尔山10条溪流在七年期间的空气和溪流温度时间序列。在溪鳟生长季节（4月至9月）计算每条溪流的热敏感性（E，空气与溪流温度关系的斜率），以确定对当地鱼类的潜在影响。就年最大生长季节温度、溪鳟热应激天数（>18°C）和估计孵化天数而言，E值在各年份内和各溪流之间有所不同。E值约为0.42作为一个拐点，高于此点热应激期急剧上升。E值也与估计孵化天数呈正相关。总体而言，本研究的数据记录了相距仅2公里的溪流对变暖的不同反应，这表明需要在地方层面采取保护措施。使用配对的溪流和河岸温度数据记录器提供了一种廉价的方法来识别和监测可能特别容易受到变暖影响的溪流。本研究的数据表明，变暖对当地东部溪鳟有不利影响，如果不考虑地下水和河岸树冠保护，以及修订放养模式，预计将持续产生生存影响。使用热敏感性等简单指标确定哪些溪流最容易受到变暖对溪鳟的影响，将使渔业/流域管理者能够更有针对性地开展保护工作，以保护这种濒危本地物种。
