Alafia River Minimum Flows and Levels - Southwest Florida Water ...

level, whenever possible. Immature or damaged specimens were identified to
the lowest level possible, given the condition of the organism. To facilitate
identification, Oligochaeta, Chironomidae, and Ceratopogonidae were slidemounted
in CMC-10, then examined at up to 100X magnification with a phasecontrast
compound microscope.
4.2.6 Fish Community Assessment and Fish Diet Analyses
Fish were collected using habitat-specific backpack electrofishing from dominant
habitats in the Alafia River corridor. The sampled area was the main stem of the
Alafia River, approximately 50 yards downstream from Vegetation Transect 64,
located within Alderman Ford Park. Three habitat types (woody debris,
overhanging root wads, and bare sand/bedrock) were selected for sampling,
based on identification of dominant habitats. On each sample date,
electrofishing was conducted in three sampling reaches, each containing all three
habitat types, resulting in nine total habitat sites per sampling trip. Sampling was
conducted during January and March 2004 via electrofishing. Fish were
collected by investigators wading downstream through each habitat. Total
electrofishing time(s) was recorded for each habitat. Upon collection, fish
samples were placed in bags and returned to the laboratory for sample
processing.
At the laboratory, fish were identified to species using fish keys and individual
fish were measured for total length (TL, mm) and weight (nearest 0.01 g).
Electrofishing catch-per-minute (CPM) was used as an index of fish abundance
for each habitat unit. Species-specific CPM values were used as an index of
relative abundance for each species at each habitat type for comparison of
richness and community composition across habitats.
Redbreast sunfish, Lepomis auritus, were separated from other species and diet
contents were assessed for individuals collected from woody debris and
overhanging root wad habitats. Fish stomachs were removed and diet contents
separated under a dissecting microscope. Prey items were identified to Order or
Family depending on the taxa. Items were counted and weighed to the nearest
0.0001 g using an Ohaus AR 2140 balance. Prey item frequency of occurrence
and mean composition by number and weight were estimated for both habitat
types.
4.3 Modeling Approaches
A variety of modeling approaches were used to develop minimum flows and
levels for the Alafia River corridor. HEC-RAS models were developed to
characterize flows at all study sites. Physical Habitat Simulation (PHABSIM)
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