Comparison of Aquatic Comparison of Aquatic Invertebrates in Pool Invertebrates in Pool and Riffle Habitats of and Riffle Habitats of

Blackburn ForkBlackburn ForkMichael RaillingMichael Railling

Department of BiologyDepartment of BiologyUndergraduate StudentUndergraduate Student

Tennessee Technological UniversityTennessee Technological UniversityCookeville, TN 38505 USACookeville, TN 38505 USA

Introduction/BackgroundIntroduction/BackgroundThe Blackburn Fork is a productive 4th order stream in The Blackburn Fork is a productive 4th order stream in

Jackson and Putnam counties (Baker 1994). On 9/14/03 a Jackson and Putnam counties (Baker 1994). On 9/14/03 a sampling effort was conducted along a 100 meter stretch of sampling effort was conducted along a 100 meter stretch of Blackburn Fork to compare macroinvertebrate community Blackburn Fork to compare macroinvertebrate community structures between pool and riffle habitats. This is the structures between pool and riffle habitats. This is the background used for the research.background used for the research.

► Stream macroinvertebrate assemblage varies at both regional and Stream macroinvertebrate assemblage varies at both regional and local scales (Heino local scales (Heino et alet al. 2003). . 2003).

► Lower water quality is directly associated to diversity (Heino Lower water quality is directly associated to diversity (Heino et alet al. . 2003). 2003).

► Abundance of the macroinvertebrates can be affected by many Abundance of the macroinvertebrates can be affected by many factors but habitat is the prime factor (Waters and Giovanni 2002).factors but habitat is the prime factor (Waters and Giovanni 2002).

► Some may prefer the larger cobble and faster currents of a riffle and Some may prefer the larger cobble and faster currents of a riffle and other may prefer the slower and bedrock substrate found in a pool other may prefer the slower and bedrock substrate found in a pool (Cushing and Allan 2001). (Cushing and Allan 2001).

► Pools generally have higher dissolved oxygen levels and a more Pools generally have higher dissolved oxygen levels and a more neutral pH. Water Qualities In pH and dissolved oxygen can have a neutral pH. Water Qualities In pH and dissolved oxygen can have a significant effect on the biota (Boto and Bunt 1981). significant effect on the biota (Boto and Bunt 1981).

Objective/Hypothesis Objective/Hypothesis StatementStatement

►Hypothesis: Hypothesis: Are aquatic macroinvertebrate Are aquatic macroinvertebrate

assemblages the same in pool and assemblages the same in pool and riffle habitats in Blackburn Fork? riffle habitats in Blackburn Fork?

►Objective:Objective:To show that different taxa are To show that different taxa are

found pool and riffle habitats using found pool and riffle habitats using taxa richness and percent EPT’s and taxa richness and percent EPT’s and percent Chironomidae.percent Chironomidae.

Methods and MaterialsMethods and Materials► 6 6 Hester-Hester-Dendy Dendy samplers were used samplers were used

qualitatively, 3 in pools and 3 in riffles.qualitatively, 3 in pools and 3 in riffles.► Two samplers from each habitat were Two samplers from each habitat were

scrubbed and seperated.scrubbed and seperated.► Invertebrates were identified to genus.Invertebrates were identified to genus.► Results were scored using data forms to show Results were scored using data forms to show

the taxa richness, percent EPT’s, and percent the taxa richness, percent EPT’s, and percent Chironomidae (Tennessee Department of Chironomidae (Tennessee Department of Environment and Conservation 2002). Environment and Conservation 2002).

Results and DiscussionResults and Discussion► In all 17 taxa were found in riffles and 11 were found in pools (In all 17 taxa were found in riffles and 11 were found in pools (Table 1Table 1). ).

Two of the taxa, Two of the taxa, AntochaAntocha and and Nigronia serricornisNigronia serricornis were found in higher were found in higher numbers in the riffle habitats. The presence of these genra is directly numbers in the riffle habitats. The presence of these genra is directly associated with higher dissolved oxygen concentrations (Weigel et al. associated with higher dissolved oxygen concentrations (Weigel et al. 2003). 2003).

► Seventeen EPT’s were found in the riffle habitats for a total of 3.78% (Seventeen EPT’s were found in the riffle habitats for a total of 3.78% (Table 2, Figure 2Table 2, Figure 2))

► The pool habitat had 26 EPT’s for a total of 3.97% (The pool habitat had 26 EPT’s for a total of 3.97% (Table 2, Figure 1Table 2, Figure 1). ). ► A total of 416 Chironomids were found in riffles; making up 92.44% of the A total of 416 Chironomids were found in riffles; making up 92.44% of the

total composition (total composition (Table 2, Figure 2Table 2, Figure 2).).► Table 2 and Figure 1 show that 627 Chironomids were found in the pool Table 2 and Figure 1 show that 627 Chironomids were found in the pool

sites making up 95.73 percent of the total composition.sites making up 95.73 percent of the total composition.► I agree with Marshall (2001) that taxa richness directly corresponds with I agree with Marshall (2001) that taxa richness directly corresponds with

water quality, however I disagree that percent EPT corresponds with the water quality, however I disagree that percent EPT corresponds with the water quality in my research.water quality in my research.

► My results back Marshall (2001) that Chironomidae are more abundant in My results back Marshall (2001) that Chironomidae are more abundant in poor water qualities.poor water qualities.

SummarySummary►3 samples were taken from pools and 3 3 samples were taken from pools and 3

from riffles riffles within a 100 meter from riffles riffles within a 100 meter stretchstretch

►The lower water quality pools had higher The lower water quality pools had higher percentage of Chironomidae, higher percentage of Chironomidae, higher percentage of EPT’s, but had less richness.percentage of EPT’s, but had less richness.

► The higher water quality riffles had higher The higher water quality riffles had higher richness, less Chironomidae, but had lower richness, less Chironomidae, but had lower percentage of EPT’s.percentage of EPT’s.