7993

• UCREFRP Catalog Number: 7993
• Author: Mabey, L. W.
• Title: Planktonic and Benthic Microcrustaceans from Floodplain and River Habitats of the Ouray Refuge on the Green, River, Utah - Master's Thesis.
• USFW Year: 1993.
• USFW - Doc Type: Brigham Young University,
• Copyright Material: NO

Results
Species richness
In all, 28 species were collected from the three habitat types (Table 3.). All
specimens were identified to species level except the cladoceran genus Alona due to
the difficulty in keying, and the harpacticoid genus Nannopus since dissections were
not successful on the few available specimens.
Only identified adult specimens are used to indicate the presence or absence of a
taxon. Acanthocyclops vernalis was found in either the plankton or benthos or both
for every sample period at all sites. Six species were found in all habitat types but not
every sample period. Seven species were unique to the floodplain. Five species were
unique to the backwaters. Only one species was unique to the river site. Ten species
were strictly planktonic. Two species were found only in the benthos (Table 3). It
should be noted that because a species is listed in only one site, it is not necessarily
absent in the other sites.
Microcrustacean densities
The total densities of microcrustaceans varied greatly within and between habitat
types (See Table 4. for plankton densities/m3 and m2 and benthic densities/m~. The
densities of plankton and benthos of the Ouray backwater ranged from 926-5,153/m2
and 4896-6,001/mz respectively. The backwater Intersection Wash had higher
densities of plankton and benthos 45,139/m2 and 23,059/m2 respectively. River
densities were lower than in the backwaters. Plankton densities ranged from 128-
11