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Correlation of Blood Parameters with Reproductive Problems in Walleyes in a Missouri Impoundment
Author(s) -
Distefano Robert J.,
Barry Terence P.,
Malison Jeffrey A.
Publication year - 1997
Publication title -
journal of aquatic animal health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 52
eISSN - 1548-8667
pISSN - 0899-7659
DOI - 10.1577/1548-8667(1997)009<0223:cobpwr>2.3.co;2
Subject(s) - stizostedion , biology , reproduction , reproductive season , reproductive success , population , fishery , positive correlation , fish <actinopterygii> , zoology , ecology , demography , medicine , sociology
Completion of the Harry S Truman Dam (HST) in west‐central Missouri in 1977 blocked a major spawning migration route for walleyes Stizostedion vitreum and flooded the historic upstream spawning area. Creel surveys, a tagging study, and population monitoring suggested problems with walleye recruitment in the HST tailwater area. The present study was part of a comprehensive project conducted to determine the status of walleye reproduction and recruitment. In walleyes from the HST tailwaters we found (1) elevated serum testosterone levels throughout the spawning season in both sexes during 1989 and in females during 1990, whereas testosterone levels normally decline at spawning; (2) elevated estradiol‐17β (E 2 ) levels throughout the spawning season in females, whereas E 2 levels normally decline; and (3) patterns of serum chloride levels indicative of fish in a state of chronic physiological stress. These preliminary findings suggest that reproductive failure of walleyes at HST may be caused by the absence of requisite environmental signals necessary for spawning or by physiological stress caused by the environmental conditions at HST, or by both factors. We suspect that changes in water temperature and flow caused by the peaking‐power water discharge regime (intermittent flows) from HST may be important factors in walleye reproductive failure in the tailwaters.