Movements and life history of sauger in Douglas Reservoir, Tennessee

A total of 30 externally-fixed transmitters were placed on 26 sauger and 4 saugeye (sauger x walleye hybrid) in Douglas Reservoir, TN. Eight sauger were tagged in December 1990, fourteen (one probably a saugeye) in February and March 1991, and eight (4 sauger and 4 saugeye) in June and July 1991. Scales were taken from 56 untagged sauger collected in 1991 for age and growth analysis.

Catch per unit effort (CPUE) for sauger caught in experimental and standard gill nets from 24 November 1990 to 13 July 1991 was 0.14 fish/hour (433.35 net hours). CPUE and TWRA cove rotenone data indicated that sauger are continuing to decline in Douglas Reservoir. The highest CPUE for sauger was recorded at French Broad River Mile (FBRM) 71-71.3, later confirmed as a spawning site. Saugeye made up at least 36% of the total number of Stizostedion sp. captured and over 50% in identified spawning areas. The presence of a large number of saugeye at the spawning ground may affect sauger reproductive success. Gill net mortality was relatively high (sauger=25 %; saugeye=47%) during June and July. No net mortality was recorded in winter and spring.

One sauger was tracked through Douglas Dam in January, 1991. This fish passed through one of the turbine intakes (sluice gates were not open at this time) and survived.

Male sauger radio-tagged in February 1991 moved upstream, showing a strong affinity for the old river channel, and were found in a shoal at FBRM 69 between March 26 and 30, 1991. Spawning was documented at FBRM 69 and FBRM 71 by the collection of eggs between March 26 and April 15.

Sauger and saugeye tagged in June and July exhibited less movement than fish tagged in winter and spring and showed a strong preference for cove habitat. Fish tagged with temperature-sensing transmitters were found in 25-28.5 C water. All fish tagged in June and July were presumed dead in August and September due to lack of movement.

Relative weights (W_r) were calculated for prespawn (W_r= 114), spawning (W_r=93), and postspawn (W_r=98) adult sauger. Relative weight values for age one (W_r=82), age two W_r,=96), age three (W_r= 101), and age four (W_r=104) sauger were also calculated. Relative weights of Douglas Reservoir sauger are "typical" or show normal fluctuations according to season or year class. Growth rate comparisons were made using back-calculated lengths. Growth rates compare favorably to northern sauger and are similar to previous records from Douglas Reservoir. However, back-calculated lengths are below average for sauger from other TVA storage reservoirs.