Date of Award
3-2017
Document Type
Thesis
Department
Biology
First Advisor
Andrew Hafs
Abstract
Research has shown that Yellow Perch Perca flavescens, found throughout lakes and streams of North America, are good indicators of environmental health. Due to the correlation between fish condition and ecosystem health it is essential to reliably estimate condition to better manage our fisheries. Therefore, the study objectives were to measure the seasonal changes in adult Yellow Perch percent dry weight (PDW), and compare the reliability of bioelectrical impedance analysis (BIA) and morphometric-based estimates of condition. The seasonal fluctuations in average monthly PDW were measured over a two- year period and were sinusoidal in shape with peaks in August 2015 (25.44 %) and July 2016 (26.34 %) when water temperatures were above 22 C. The valleys occurred in February 2015 (22.73 %) and April 2016 (22.96 %) when temperatures were below 5 C. When the best supported BIA lab model was used to estimate condition of Yellow Perch in the lab it explained 18 % more of the variation in PDW (R2 = 0.60; RMSE = 0.92) when compared to morphometric-based models (R2 = 0.42; RMSE = 1.09). BIA and morphometric-based models were unable to reliably estimate condition of Yellow Perch measured in the field (R2 ≤ 0.18). The sources of error associated with standard fish condition estimates need to be identified and methods improved if we are to successfully manage our local and global fisheries.
Recommended Citation
Powers, Emily Anne, "Estimating Seasonal Variation in Condition of Yellow Perch" (2017). Biology Graduate Theses. 13.
https://pines.bemidjistate.edu/thesis-biol/13
Included in
Animal Experimentation and Research Commons, Aquaculture and Fisheries Commons, Biology Commons, Environmental Health and Protection Commons, Environmental Monitoring Commons, Laboratory and Basic Science Research Commons, Natural Resources and Conservation Commons, Population Biology Commons, Terrestrial and Aquatic Ecology Commons
