Benthic Macroinvertebrate Assemblages in Flint River, Indian Creek and Flint Creek Watersheds in North Alabama- Preliminary Study

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Benthic Macroinvertebrate Assemblages in Flint
River, Indian Creek and Flint Creek Watersheds in
North Alabama- Preliminary Study R. Ward, L.
White, A. Bohlman and T. Tsegaye Department of
Plant and Soil Science, Alabama AM
University P.O. Box 1208, Normal, AL 35762
Abstract Benthic macroinvertebrates are
excellent indicators of water pollution such as
turbidity and nutrient loads. The assessment of
aquatic biodiversity is widely used to strengthen
continuing measures of water quality in north
Alabama. This preliminary study was conducted to
determine taxa richness (total number of taxa)
and composition of aquatic insects occurring in
Flint River, Indian Creek and Flint Creek. For
this report, bioassessment was based mainly on
the relative abundance of EPT and chironomid
percent Ephemeroptera-Plecoptera-Trichoptera
(EPT) and percent chironomids. EPT are known to
be highly sensitive to increasing perturbations
increase in their abundance suggest improved
water health. The occurrence and dominance of
chironomids, on the other hand, may indicate
organic impairments of streams. Twenty seven
families have been identified in our sample
collections suggesting the rich diversity of
biotic components in the watersheds under study.
In this study, spring-summer aquatic insect
samplings were done at monthly intervals in three
locations along each tributary using surber, dip
net, kick net and leaf pack methods. In addition,
gastropod presence in the watersheds was also
recorded. The sampling sites also represent the
diverse riparian zones and land use of the
surrounding areas. Our preliminary results showed
high dominance of Ephemeroptera over stonefly and
caddisfly populations in all watersheds.
Chironomids and simuliids comprised the majority
of the Dipterans collected. Likewise, Elmidae
(riffle beetles) has a strong presence in all
watersheds. Riparian and stream characteristics
were described for each sampling location.
Sample Sites Watershed Site Location Description
1. B.W. Road 2. 3 -Forks 3. FR on Hwy 72 4. Providence Main 5. Farrow Road 6. Old Madison Pike 7. Lacon, AL 8. Bankhead N.F. 9. Neel, AL Flint River Flint River Flint River Indian Creek Indian Creek Indian Creek Flint Creek Flint Creek Flint Creek Mostly agricultural, variable riparian widths, moderate canopy cover, high siltation. High residential, wide riparian widths, too wide for complete canopy reach, remnants of old bridges Mostly agricultural, expanding residential developments, public access accumulates trash, complete canopy, mixed substrate On new greenway space off of poorly contained community development, stable riparian area, large snags throughout reach On new greenway space through high residential area. Thin riparian area, highly shaded, mostly cobble bottoms South of IC Greenway and current construction, large riparian buffers, balanced ratio of riffles, pools, some bedrock In bottom hardwood forested/wetland, sandy bottoms, many snags and embankments, very low flow during dry season Within established preserve wilderness area, ephemeral flow, well shaded by canopy, mix sandy and cobble substrate Near some residential and wetlands, small intermittent stream, sandy mud bottom, previously channelized, high (gt2.5 m) banks
RESULTS Each of the sampling sites is described
in Table 1. On the Flint River, collection sites
were near agricultural lands and expanding
residential rural developments most effluents
were from adjacent agricultural farms. Indian
Creek is situated in heavily populated urbanized
sections of the City of Huntsville two sites on
this watershed bordered green space areas. Urban
sprawl and sedimentation contribute significantly
to the deterioration of water quality in this
tributary. Flint Creek is a designated EPA
cleanup site it is heavily channelized through
agricultural pasture lands but two of the
collection sites are located in hardwood
forested/wetlands. All of these reaches are
intermittent their flow slowed, developing into
shallow pools during the dry season. Twenty
seven families in 7 orders were represented in
our composite collections (combined watersheds)
(Table 2). Among EPT, Ephemeroptera dominated
other groups at 29 of total individuals
collected (Figs. 1-3) families Heptageniidae and
Hydropsychidae (Trichoptera) led the group in
abundance across watersheds. Stoneflies were
practically absent in the study sites Plecoptera
was represented by only one family (Perlidae) at
3.17. Caddisflies (Trichoptera) had a healthy
presence in the watersheds at 15.70. Although
combined EPT dominated all other insect groups,
Diptera (17.82 ) closed in second to mayflies in
abundance. Chironomids ranked fourth among top
families in all watersheds suggesting organic
stream impairment. Indian Creek (Providence)
topped all other sites for number of chironomids.
The site is in the center of a massive urban
sprawl adjacent areas are currently undergoing
expansive business and residential development.
The xylophagous riffle beetles (Elmidae) occurred
in all watersheds. With Heptageniidae, Elmidae
ranked first (at 14) among top 11 families in
the all watersheds (Fig. 1). Simuliids were
predominant in Flint Creek (Fig. 4), occurring in
moderate numbers elsewhere.
INTRODUCTION Flint River, Indian Creek and
Flint Creek are major tributaries to
the Tennessee River which supplies drinking water
and provides recreation areas to residents of
Madison and other counties in north Alabama. The
quality of water draining from these watersheds
is of prime importance to the public. Benthic
macroinvertebrates vary in their sensitivity and
tolerance of pollutants occurring in bodies of
water. These organisms respond to long term
impairments of stream water. Unlike chemical
water parameters which are reflective of water
condition at time of sampling, population levels
of aquatic fauna respond to long term effects
due to their stabilized water environment. Thus,
as bioindicators, aquatic insects are excellent
and reliable determinants of the general health
of streams and rivers. Members of the orders
Ephemeroptera (mayflies), Plecoptera
(stoneflies) and Trichoptera (caddisflies) are
intolerant of pollutants their relative
abundance indicates good water quality. Midges
and blackflies both are in the order Diptera
(flies) are tolerant of pollution their
occurrence in high numbers is indicative of
water impairment.
Table 1. Description of sampling sites.
Identified Families Number of Individuals Percent
Ephemeroptera Heptageniidae, Ameletidae, Baetidae, Caenidae, Ephermerillidae, Empididae 365 29.70
Diptera Chironomidae,Tipulidae,Tabanidae, Simuliidae, Dixidae, Athericidae 219 17.82
Trichoptera Hydropsychidae, Philopotamidae, Polycentropodidae, Psychomyiidae, Leptophlebiidae 193 15.70
Coleoptera Psephenidae, Elmidae 166 13.51
Odonata Coenagrionidae, Gomphidae, Aeshnidae, Calopterygidae, Libellulidae 141 11.47
Gastropoda N/A 106 8.62
Plecoptera Perlidae 39 3.17
Total 1229 100.00
METHODS (Contd.) Dip Net Both sides of the
stream bank were sampled for aquatic insects
using 10 jabs of dip net along the stream within
the sampling site. Samples were combined for
collections on each side of the stream. Leaf
Pack Leaf packs were collected from each half
of the stream into a composite sample (300-500 g
wet weight). Leaf packs provide suitable habitat
and nutrition for a variety of macroinvertebrates.
Each collected leaf pack was hand-picked for
clinging invertebrates. Kick Net - Three
riffles were sampled with a 1-m kick net.
The substrate was disturbed approximately 3
meters upstream of the net. The invertebrates
were handpicked after each kick. Sampling
Sites The general geophysical characteristics of
the collection sites canopy cover (), riparian
vegetation, stream disturbances, etc. were
noted. Field parameters recorded include stream
depth (cm), water temperature (C), pH, turbidity
(FAU), total dissolved solids (ppm) and dissolved
oxygen (mg/L). All macroinvertebrates were
initially preserved in 75 ethyl alcohol, brought
back to the laboratory, sorted, identified to
family, and placed in 90 ethanol in glass
vials. Parameters For this report,
bioassessment was based on percent () EPT for
each sampling site and for all watersheds
combined. Percent chironomids and simuliids were
measured similarly. Other parameters (e.g., total
taxa, diversity indices, etc.) will be used in
subsequent data analyses.
METHODS Study Watersheds Flint River, Indian
Creek and Flint Creek Three sampling sites, each
100 m long reach, were selected for each
watershed. For Flint River , the sites were on
Hwy 72, Buddy Williams Road, and 3 Forks. For
Indian Creek, Old Madison Pike, Farrow Road, and
Providence Main were chosen. Lacon, AL, Neel,
AL, and the Bankhead National Forest were
selected for Flint Creek. Sampling Methods Each
site per watershed was sampled monthly. Sampling
was based on EPA Rapid Bioassessment Protocols
(RBPs) multi-habitat methods (USEPA 2006).
Macroinvertebrates were collected from a variety
of microhabitats using different techniques. All
sampling methods were begun downstream, moving up
the reach to minimize disturbance. Surber Each
site per watershed was divided into 3 sections
with riffles along the length of the stream from
which three samples were collected. Each sample
was a composite of three sub-samples obtained by
rubbing substrate (gravel and cobbles) for 1
minute to dislodge aquatic insects. Insects were
individually picked using forceps or camels
hairbrush from the mesh.
Table 2 . Major groups collected in study areas.

• SUMMARY
• A total of 27 families were collected in all
  watersheds combined top 9 included
  Heptageniidae, Elmidae, Hydropsychidae,
  Chironomidae, Ameletidae, Baetidae, Simuliidae,
  Coenagrionidae and Caenidae.
• Indian Creek (Madison Pike) had the highest
  EPT compared to other watersheds however, this
  watershed (Providence Main) also harbored the
  highest number of chironomids.
• Based on relative EPT abundance ( EPT) and low
  numbers of chironomids as bioindicators of
  pollutants, Flint River (Hwy 72) has the highest
  water quality of all watersheds under study.
• Top 6 families account for 53.18 top 11
  families account for 84.24.

LITERATURE CITED U.S. EPA. 2006. Rapid
Bioassessment Protocols for use in Streams and
Wadeable Rivers Periphyton, Benthic
Macroinvertebrates, and fish. http//www.epa.gov/o
wow/monitoring/rbp/index.html