9323

• UCREFRP Catalog Number: 9323
• Author: Cooper, D. J. and C. Severn.
• Title: Wetlands of the Ouray National Wildlife Refuge, Utah
• USFW Year: 1994.
• USFW - Doc Type: Hydrology, Water Chemistry, Vegetation, Invertebrate Communities, and Restoration Potential.
• Copyright Material: NO

Benthic chironomid larvae were found in all but the flooded
cottonwood community (Figure 16). Densities were greatest in the
open water community followed by the backwater, river, and
bulrush communities. Other benthic invertebrate densities
(including Gastropoda, Nematoda, Odonata, Hemiptera, Culicidae,
Ephemeroptera, and Coleoptera) were greatest in the bulrush
community followed by the river and open water communities.
Other benthic invertebrates were not found in any benthic samples
of the open water and flooded cottonwood communities.
Water column and benthic invertebrate densities for each
community station are presented in Figure 17. Flooded cottonwood
station 012 had by far the greatest mean density of water column
invertebrates for all stations with 205 organisms L'1. Other
flooded cottonwood stations had water column densities well below
that seen at 012. Mean densities of water column invertebrates
were generally higher at open water stations than stations of
other communities. Open water station 09 at Wyasket Lake had the
greatest density for this community with 65 organisms L'1 and was
closely followed by open water station 010 (Wyasket Lake) and 015
(Old Charlie) with 58 and 53 organisms L'1, respectively.
Bulrush stations had more moderate densities of water column
invertebrates with 03 and 02 having 28 and 27 organisms L'1,
respectively. Water column invertebrates at backwater and river
stations were all well below densities seen at stations of other
communities (not apparent due to graph scale), none exceeding
0.15 organisms L-1.
Benthic invertebrate densities appear to be much more
variable both among and within community stations. Highest
densities of benthic invertebrates were seen at open water
station 015 with 75 L'1 closely followed by bulrush station 02
with 73 organisms L'1. Benthic invertebrates were not found in
samples at the flooded cottonwood stations or at bulrush station
03 throughout the season. Benthic invertebrates at backwater
station 016 were the highest for any of the riverine communities
having 29 organisms L'1, but at station 06 which was sampled only
once, benthic .invertebrates were not found in samples. Ranges
for benthic invertebrates in the river community were between 4.3
and 26 organisms L'1 at stations 06 and 013, respectively.
26