Thermal tolerance of aquatic insects inhabiting the Tennessee River-Reservoir system

Technical Report · Tue Mar 01 04:00:00 EST 1983

DOI:https://doi.org/10.2172/5835632· OSTI ID:5835632

Tennessen, K. J.; Miller, J. L.

The objectives were to (1) determine the short-term thermal tolerance of several important species of aquatic insects in the Tennessee River-Reservoir system, (2) investigate the effect of acclimation temperature on tolerance, and the possibility of delayed mortality, (3) determine the most sensitive stage in the life cycle, and (4) conduct field studies on growth and emergence of selected aquatic insects within actual thermal plume areas. In laboratory tests, nymphs of Hexagenia bilineata (Ephemeroptera) and larvae of Chironomus crassicaudatus (Diptera) were highly tolerant of short term thermal shocks (six hour duration, simulating entrainment in a thermal plume and drifting to ambient). TL50 values increased from 35/sup 0/C at an acclimation temperature of 5/sup 0/C to 38 to 40/sup 0/C at an acclimation temperature of 20 to 25/sup 0/C. However, survivors of these treatments experienced higher percentages of delayed mortality compared to controls after being held for ten days to four weeks at the original acclimation temperature. The most senstitive stage found in the life cycle of H. bilineata was the egg during oviposition (time of fertilization); eggs exposed to 33/sup 0/C for 15 minutes during oviposition hatched at a significantly lower percentage than controls (ambient was 28/sup 0/C). The data generated indicate that aquatic insect species inhabiting TVA's large warm-water reservoirs are living close to their thermal maximum, and that an upper limit of 33/sup 0/C would ensure the maintenance of sizeable populations of the species studied.

• Research Organization: Tennessee Valley Authority, Muscle Shoals, AL (USA). Office of Natural Resources
• OSTI ID: 5835632
• Report Number(s): TVA/ONR/WRF-83/10; EPA-600/7-83-020; ON: DE83902903
• Country of Publication: United States
• Language: English

Related Subjects

520400 -- Environment
Aquatic-- Thermal Effluents Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
560204* -- Thermal Effects-- Invertebrates-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
AQUATIC ORGANISMS
ARTHROPODS
BIOLOGICAL ADAPTATION
DATA
ENVIRONMENTAL IMPACTS
EXPERIMENTAL DATA
INFORMATION
INSECTS
INVERTEBRATES
METAMORPHOSIS
MORTALITY
NUMERICAL DATA
POWER PLANTS
RIVERS
SENSITIVITY
STREAMS
SURFACE WATERS
TEMPERATURE EFFECTS
TENNESSEE RIVER
THERMAL EFFLUENTS
THERMAL POWER PLANTS
TOLERANCE
WATER RESERVOIRS