Ecological Consequences of Hypoxia for Yellow Perch (Perca Flavescens) in Lake Erie.

Hypoxia;Yellow Perch;Lake Erie;Dead Zone;Ecology and Evolutionary Biology;Natural Resources and Environment;Science;Natural Resources and Environment

Roberts, James J.Werner, Earl E. ;

University of Michigan

关键词: Hypoxia;    Yellow Perch;    Lake Erie;    Dead Zone;    Ecology and Evolutionary Biology;    Natural Resources and Environment;    Science;    Natural Resources and Environment;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/75890/jjrobert_1.pdf?sequence=1&isAllowed=y

瑞士|英语

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

【 摘 要 】

Hypoxia (<2 mg O2•L-1) is a widespread phenomenon in marine and freshwatersystems worldwide, yet the ecological consequences of hypoxia are generally unknown,especially for mobile species such as fish. Areas of hypoxic conditions or ;;dead zones”,due primarily to eutrophication (i.e. nutrient enrichment), are viewed as a major threat toaquatic ecosystem function worldwide. Areas of bottom water (hypolimnetic) hypoxiahave long been documented and are increasing in the Lake Erie ecosystem, aneconomically and ecologically important water body within the Laurentian Great Lakes.Quantifying the ecological consequences of hypoxia for highly mobile organisms (e.g.,yellow perch Perca flavescens) is a complex task. Such organisms are capable ofavoiding direct lethal effects of hypolimnetic hypoxia, but may be indirectly affected asthey are forced to occupy inferior habitats (i.e., novel prey, predators, competitors andphysical conditions). I used field, and laboratory techniques to address the overallhypothesis that hypolimnetic hypoxia in Lake Erie negatively affects yellow perch.Laboratory results suggest yellow perch growth and consumption are negativelyaffected by low oxygen conditions. However, my field results suggest yellow perchattempt to mitigate these potential consequences by altering their distribution andforaging patterns in the presence of hypoxic conditions. My results also suggest a changein the sub-daily behaviors of yellow perch. This behavioral change involves short-termforays to forage within hypoxic habitats. The largest consequence of hypoxia for yellowperch in LECB is altered distribution patterns due to vertical or horizontal migrations inavoidance of low oxygen conditions. Overall, it appears hypoxia has the potential tonegatively affect yellow perch however, behavioral modifications allow yellow perch tomitigate the extent of these consequences in Lake Erie. These results will havemanagement implications for Lake Erie resource agencies and provide importantconclusions concerning the ecological consequences of hypoxia for freshwater fishes.