Land use drives the physiological properties of a stream fish

land use;land cover;stream fish;stress;physiology;acclimation;human disturbance

Blevins, Zachary ; Suski ; Cory D. ; Wahl ; David H.

关键词: land use;    land cover;    stream fish;    stress;    physiology;    acclimation;    human disturbance;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/34486/Blevins_Zachary.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Human activities within the riparian zone can alter the abiotic properties of watersheds and stream reaches, potentially resulting in abiotic conditions that are stressful for resident fishes.The inability of fish to cope physiologically with stressful abiotic conditions can have deleterious effects on individuals, and could potentially lead to population declines or changes to community structure.Defining links between the landscape and performance of individual stream fishes can therefore improve our ability to predict how land use changes can impact stream communities, which has relevance for management activities.These studies tested the hypothesis that land cover at the watershed and reach scale influence the physiological stress response of a resident stream fish.For this, replicate streams in agricultural watersheds and forested watersheds were identified for the watershed-scale study and replicate forested and agricultural stream reaches were identified for the reach-scale study.In both the watershed and reach-scale studies, sampling demonstrated that streams in agricultural watersheds and stream reaches were warmer and more thermally variable than those from forested areas.In the watershed-scale study, creek chub from each land use type were sampled for blood and muscle in the field, following exposure to thermal and oxygen stressors in the laboratory, and after prolonged holding at elevated temperatures that replicated field conditions.In the reach-scale study, creek chub from each land use type were sampled for blood and muscle in the field, following exposure to thermal stressors in the laboratory. Results from both studies were similar as no differences in baseline physiological parameters were found in fish sampled directly from streams.However, when exposed to high temperature and low oxygen conditions (watershed-scale study exclusively) in the laboratory, creek chub from streams within agricultural areas maintained physiological performance with a reduced stress response relative to creek chubs from streams within forested watersheds.In addition, acclimation to high temperature removed landscape-level differences in stress responses, resulting in improved physiological performance for all fishes after a heat challenge.Results indicate that creek chub have the ability to adjust physiological responses to improve performance in disturbed environments, and also provide a novel mechanism by which landscape-level processes can influence biodiversity.