HABITAT ASSESSMENT METHODOLOGY AND COMPARISON
 OF THREE TENNESSEE STREAMS

 Greg Harris and  Mack Finley

The Center for Field Biology, Austin Peay State University, Clarksville, TN, 37044

      ABSTRACT. Physical habitat description is necessary before any biological monitoring is performed.  The Environmental Protection Agency (EPA) has set standards for performing habitat assessments.  Evaluating in-stream and out-of-stream parameters can assist in identifying problems that may exist in a particular watershed.  Habitat assessment data along with biological and chemical data can give an overall view of water quality.  The purpose of this study was to show the different stream types across the state of Tennessee.  Habitat assessments were performed in three Tennessee streams.  Each stream was divided into three 100 meter reaches and designated as upper, middle, and lower.  A habitat assessment evaluation was performed in each stream reach.  An Eastern stream was evaluated as a high gradient (high velocity) while Middle and Western streams were evaluated as low gradient (low velocity) streams.  Once the assessments were complete, photographs were made of the different physical habitats of these different streams.

CHARACTERISTICS OF ZOOPLANKTON DIAPAUSE
IN A RESERVOIR ECOSYSTEM

Christopher J. Albritton, David S. White

 Department of Biological Sciences, Murray State University, Murray, KY, 42071

       ABSTRACT.  The eggs of many freshwater zooplankton species diapause in lake bottom sediments throughout much of the year.  Some eggs may withstand drying when bottom sediments are exposed and hatch when sediments are rewetted.  The extensive water level fluctuations that often occur in reservoir ecosystems may give a survival advantage to species of zooplankton with diapausing eggs.  This study examined the effects of drying and rewetting on egg banks in three types of Kentucky Lake sediment: a littoral zone with an annual drying and wetting cycle, a permanently wetted embayment, and a floodplain that is only rarely inundated.  We concluded that desiccation and rewetting were cues for the rotifers Lecane, Lepadella, Keratella, and Monostyla, for the cladoceran Diaphanasoma, and for ostracods.  The eggs of many other species common in the reservoir did not respond to desiccation, signifying either their need for other environmental cues or lack of viable eggs in the egg bank.  Sediments located in either the littoral zone or floodplain that normally experienced drying and rewetting cycles showed greater species diversity and number of total individuals hatched than permanently wetted sediments.  The number of hatching eggs increased with depth into the sediment up to at least 20 cm.  Hatching success in response to drying and rewetting demonstrates that diapause plays a role in zooplankton dynamics of this reservoir ecosystem.  Present studies are analyzing both drying and freezing effects on the breaking of egg diapause.

TRICHOPTERAN SURVEY OF BRUSH CREEK, ROBERTSON COUNTY, TENNESSEE: A PRELIMINARY REPORT

 K. Davenport and S. W. Hamilton

The Center for Field Biology, Austin Peay State University, Clarksville, TN 37044

         ABSTRACT.  Caddisflies (Insecta: Trichoptera) were sampled from Brush Creek in Robertson County, Tennessee from May 1999 to October 2000.  Brush Creek is a third order tributary of Sulphur Fork Creek and Red River in the Western Pennyroyal Karst region of the Interior Plateau.  Caddisflies are an important part of the food web in fresh water environments and serve as bioindicators in the assessment of water quality.  Adults were collected using ultraviolet light traps and males were identified to species.  A total of 71 species representing 32 genera and 14 families have been identified to date.  Based on checklists of Tennessee and Kentucky caddisfly fauna and the preliminary data thus far obtained, this poorly surveyed area appears to have a moderately rich trichopteran fauna.

EVALUATION OF AMONG-RIFFLE VARIANCE ON MULTIMETRIC BIOASSESSMENT USING MACROINVERTEBRATE ASSEMBLAGES
OF THREE MIDDLE TENNESSEE STREAMS

Rebecca Houtman, Joseph R. Schiller and Steven W. Hamilton

The Center for Field Biology, Austin Peay State University, Clarksville, TN 37044

       ABSTRACT.  The United States Environmental Protection Agency has published Rapid Bioassessment Protocols (RBP) for assessing the biotic integrity of streams.  These techniques employ several ecologically relevant measures of community structure and function, i.e. metrics, considered to be sensitive to stream degradation.  The metrics are selected to cover a wide range of structural and functional properties of aquatic biological communities. The preliminary data of this study tests the implied assumption that sampling two riffles of a single stream reach provides an accurate representation of the macroinvertebrate assemblage of the stream and therefore a reliable bioassessment.  Five riffles were sampled in a single stream reach of three streams.  Of eleven metrics evaluated, mean values of six varied significantly among streams; however, metric values often varied greatly among riffles within each stream and the range of metric values within streams often overlapped among streams.  Thus bioassessments based on any set of single riffle sample from each stream could be expected to yield inconsistent results.

MICROBIAL DIVERSITY OF THE LITTORAL ZONE OF LEDBETTER
CREEK EMBAYMENT, KENTUCKY LAKE

Suzan Barton¹ and Timothy Johnston²

¹The Department of Chemistry and the ²Department of Biological Sciences

Murray State University, Murray, KY 42071

       ABSTRACT.   A group of faculty associated with the center for Reservoir Research, Murray State University, was awarded a C-RUI grant that began in January 2000. The grant provides funds for students to study the effects of human controlled water fluctuations on ecosystem function in a major reservoir littoral zone, at several trophic levels.  A portion of the project seeks to access the influence of water fluctuation on the microbial community and its activity.  Thomas Moore, under the direction of Dr. Susan Hendricks, is assessing bacterial productivity by thymidine uptake and assaying for a battery of exoenzymes.  Terry Ray, under the direction of Dr. George Kipphut, is measuring chemical flux in and out of sediment to the water column using closed chamber experiments.  We are assessing the microbial diversity and microbial succession by restriction endonuclease digestion band pattern analysis of amplified rRNA genes (ARDRA).  We have collected samples from the littoral zone of Ledbetter Embayment as the water level was dropped to winter pool, isolated DNA directly from the sediment, amplified rDNA by PCR, and analyzed restriction endonuclease fingerprints of those samples by ARDRA.

MORPHOLOGICAL PLASTICITY OF PHYSID AND PLUEROCERID SNAILS IN THE LEDBETTER EMBAYMENT

 Amanda Crook and Howard Whiteman

Department of Biological Sciences, Murray State University, Murray, KY 42071

       ABSTRACT.  Plasticity allows organisms to mitigate the effects of variable environments.  Due to low mobility and the fact that they cannot readily change their habitat, plasticity plays an important role in the life of snails.  For example, previous studies have shown that physid snails exhibit predator-induced morphology shifts in the presence of crayfish and pumpkinseed sunfish, two of its major predators.  My research was conducted in the littoral zone of Ledbetter embayment on Kentucky Lake.  This environment is one of human induced water level fluctuations.  The two predominant snail species in the area are Physella and Elimia.  Using morphometric software I am measuring shells collected from the embayment at different depths and locations and determining if these snails are exhibiting morphological plasticity.

CRAYFISH ECOLOGY OF LEDBETTER EMBAYMENT

 Joanna L. Kind and Howard Whiteman

Department of Biological Sciences, Murray State University, Murray, KY 42071

       ABSTRACT.   Although natural lakes and ponds have been studied extensively, little research has been conducted on reservoir ecosystems.  This is surprising, given that reservoirs are the dominant freshwater environment in much of the world.  I chose to study crayfish distribution in Ledbetter Embayment of Kentucky Lake, a reservoir on the Tennessee River.  Crayfish are opportunistic omnivores that feed on a wide variety of plant and animal material, and thus play an important ecological role as detritivores.  Each Sunday evening from June until early August, 14 cylindrical minnow traps were baited with chicken liver suspended in mesh bags.  These traps were set 10 meters apart in the littoral zone to cover a wide variety of habitats and depths.  The next morning, the traps were checked and the crayfish were identified, sexed, and measured.  Surface temperature and lake levels were also recorded for each date.  Each trap site was GPSed and all data was logged into a database, which was connected to a global information system (GIS).   Procambarus acutus was the only species recovered in the traps, with more than 400 individuals captured.  Evidence thus far suggests that crayfish distribution changes seasonally with water level fluctuations, but is more closely related to water temperature than lake level.  Thus, the ecological role of crayfish within reservoir littoral zones varies both with anthropologic impact (lake level) and natural (temperature) environmental change.

SEDIMENT-WATER FLUXES OF NUTRIENTS AND DISSOLVED
GASES IN KENTUCKY LAKE RESERVOIR

G. W. Kipphut¹, H. M. Richard², G. Ridout³, and T. Ray⁴

 ¹Center for Reservoir Research, ²Water Science Program,
 ³Department of Biological Sciences, and ⁴Department of Geosciences,
 Murray State University, Murray, KY 42071

       ABSTRACT.   We have been measuring sediment-water fluxes of dissolved nutrients and gases in Kentucky Lake, the largest reservoir within the Tennessee River Valley. These studies have been conducted as part of a larger project assessing biogeochemical processes affecting carbon accumulation, metabolism, and mineralization within Kentucky Lake. Approximately thirty flux measurements have been made with benthic chambers. Sediment-water fluxes are strongly dependent on water temperature. Nitrogen and phosphorus fluxes from the sediments to overlying waters are significant in terms of reservoir ecology. We estimate that the sediment-water fluxes supply the majority of the nutrient requirements of primary production within the water column during the summer season. Sediment-water fluxes of phosphorus occur even though the water column is always well oxygenated in this un-stratified reservoir. Concurrent studies are attempting to relate these chemical fluxes to microbial activity in the sediments. The Kentucky Lake water column is supersaturated with carbon dioxide and methane with respect to atmospheric exchange. Benthic chamber measurements suggest that the sediments are a significant, but not the only source for these gases to the water column.

KENTUCKY LAKE WATER PARAMETERS FROM SPECTRORADIOMETER
AND LANDSAT TM DATA

 Burl I. Naugle

 Department of Geoscience, Murray State University, Murray, KY 42071

       ABSTRACT.  The major objective of this study was to assess quantitatively and spatially map the suspended sediment concentration, turbidity, and chlorophyll in the lower reaches of Kentucky Lake.  Suspended sediment, turbidity, and chlorophyll readings from several sample sites were obtained for four dates from 1998 and 1999.  Landsat TM data of Kentucky Lake from those dates were acquired and utilized to map total suspended solids (TSS), turbidity, and chlorophyll for the reservoir based on correspondence with the sampled data.  Spectroradiometer data were also obtained for some study sites and some of the dates and were analyzed for correspondence with the sample data and the TM data.

      The total suspended solid (TSS) values, turbidity, chlorophyll, and corresponding TM spectral responses for the first five reflective bands at each sample site for the four data sets were then entered as input to the SAS analysis package and equations to model water parameters were generated.  Several models were obtained for each data set: the best single band and the best multi-band.  A similar process was followed for the spectroradiometer data.  The multi-band TM models for both original data sets exhibited superior performance in predicted suspended sediment and turbidity trends in comparison to the single band models.  After removing a few sample points with large residuals multiple correlation coefficient values (R²) of over 0.5 were obtained for all models.  Regression models for each date were significantly different.  Atmospheric correction of the TM data was attempted using several methods, including utilizing the spectroradiometer data, but very limited success has been achieved to date.  On the other hand the spectroradiometer data did result in much better regression models than those from the TM data in all cases.