Don Dennerline, University of Georgia Cooperative
Fish and Wildlife Research, Unit D.B. Warnell School of Forest Resources, Athens, Georgia
30602-2154; Voice 706-542-4988; FAX 706-542-8356;
E-Mail dennerli@smokey.forestry.uga.edu
Don Degan, 816C Brawley School Rd, Mooresville, North Carolina 28115;
Aquacoustics Voice 704- 664-7737; FAX 704-662-3536;
E-Mail djdegan@worldnet.att.net
Keywords: blueback herring, Alosa, Thurmond Reservoir,
distribution, stratification
Previous work in J. Strom Thurmond reservoir during stratified periods
showed that blueback herring were vertically distributed in strata where water
temperatures were 18o to 24o C and dissolved oxygen content was >
3 ppm. Furthermore, there was evidence that distribution of blueback herring along the
longitudinal axis of the reservoir was limited, in some years, by the absence of cool,
oxygenated water in the lower half of the reservoir. Previous data were not sufficient to
evaluate possible relationships between densities of blueback herring and volume of
suitable habitat. From June to September 1998, blueback herring were sampled concurrently
with vertical gill-nets and hydro acoustics to determine if densities of blueback herring
were constant (within desirable water quality strata) throughout the lake. Alternatively,
we wanted to determine if blueback herring distribution during summer stratification was
predictable based solely on the distribution of suitable habitat. Lastly, we wanted to
evaluate the relationship between the catch rate of blueback herring from gill-nets and
the density estimates from mobile hydro acoustics.