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Environmental Influences on Walleye Fingerling Production in Southwestern Minnesota Shallow Lakes
Author(s) -
Ward Matthew J.,
Fisher Shan J.,
Willis David W.
Publication year - 2007
Publication title -
north american journal of aquaculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 41
eISSN - 1548-8454
pISSN - 1522-2055
DOI - 10.1577/a06-030.1
Subject(s) - fishery , hatchery , abiotic component , productivity , biology , wetland , zooplankton , environmental science , ecology , fish <actinopterygii> , economics , macroeconomics
Shallow lakes and deep wetlands in southwestern Minnesota are being used as rearing ponds for fingerling walleye Sander vitreus ; however, information about the biotic and abiotic variables that influence walleye rearing success in these water bodies is limited and inconsistent. Our objective was to identify the characteristics that most influence fall walleye fingerling production in southwestern Minnesota lacustrine wetlands. We used principal component analysis to reduce the dimensionality of the data set. A subsequent correlation analysis using the created independent variables (i.e., principal components scores) indicated that walleye fingerling production measures were positively related to total phosphorus, chlorophyll a , and total Kjeldahl nitrogen and negatively associated with Secchi disk depth and water conductivity ( r = 0.70–0.74). Invertebrate densities, particularly that of zooplankton, exhibited weak but positive associations with walleye fingerling production ( r = 0.48–0.57). The negative influence of other fishes on fingerling production was evident, as fish community species richness was negatively correlated with walleye fingerling production indices ( r = −0.75 to −0.48). Adequate prey resources, elevated productivity indices, and the absence of a fish community were thus important characteristics for selecting potential walleye fingerling rearing ponds. In addition, walleye fry that were taken from the hatchery in excellent condition, displayed heavy pigmentation, demonstrated a high activity level, and exhibited uniform distribution during transport enhanced walleye fingerling production.