8172

• UCREFRP Catalog Number: 8172
• Author: Jacobi, G. Z., J. E. Sublette, S. J. Herrmann, D. E. Cowley and M. D. Hatch.
• Title: Final Report
• USFW Year: 1998.
• USFW - Doc Type: Investigations of an Index of Biotic Integrity in New Mexico.
• Copyright Material: NO

area. Group B contained species that were
found in the Costilla River system, and,
Group C contained species found in the Rio
Grande below Cochiti Lake. Group D was
a composite of species from the Costilla
River and the Los Pinos River. Group E
represented the 22 species that were unique
to the Chama River above the town of
Chama, and, Group F was predominantly
-species that -were-unique -to •Casias • Creek
(Costilla River tributary).
The third cluster was composed of four
subgroups labeled G-J (Figure 12a). Group
G species were characteristic of sites in the
middle section of the Chama River. Group
H represented species from the Jemez
River, and, Group I was lower Chama
River species. Group J was predominantly
species found in the Chama River below El
Vado Reservoir.
The chironomid species associations defined
by cluster analysis are representative of the
cold-water chironomid faun in northern
New Mexico. The fauna of cluster 2 is
dominated by the members of the
subfamilies Diamesinae and Orthocladiinae
in terms of species diversity, while cluster 3
has a reduced number of orthocladine
species and an, increased number of
Chironominae. The numbers of chironomid
species in five subfamilies are given in Box
3.
In a broad sense, the chironomid species
associations indicate (1) widespread species,
(2) cold water species, and (3) warmer
water species. The results also indicate that
at a finer scale chironomid species
associations display a high degree
specificity to individual streams. Within the
Chama River, there appears to be specificity
in species associations to individual reaches
of the river.
Box 3. Distribution of chironomid
subfamilies for species associations 2
and 3 obtained with cluster analysis.
CLUSTER 2 CLUSTER 3
Dias iaae (a)
Orthocladiinae (SO
Chisonasime (1S)
Prodiaaieeiaae (2)
TanYpadinae (a)
Diaeeeloae (1)
Orthocladiiaaa (25)
Chironoainae (37)
Prodia"aiaae ll)
Tanypodinae (5) -
Bentldc Macroinvertebrates
Taxonomic associations of benthic
macroinvertebrates were obtained by cluster
analysis on presence/absence data (Figure
13). Three major associations were
evident. Cluster 1 was represented by
widespread taxa, such as those of
intermediate tolerance, e.g., mayflies
(Baeddae), black flies (Simuliidae),
caddisf ies (Hydrophychidae and
Brachycentridae), and riffle beetles
(Elmidae). Macroinvertebrates found in
Cluster 1 were also generally abundant and
in many cases were the dominant taxon.
Cluster 2 included many benthic
macroinvertebrate taxa that were found
more often at lower elevations (Aquatic
Ecoregion 2). Cluster 2a macroinvertebrates
were more tolerant of degraded
environments and they were indicative of a
variety of habitats ranging from boulders,
rubble, to gravel with fine interstitial
material. These benthic macroinvertebrates
are typical in areas with higher total
dissolved residues (MR), bicarbonates, and
alkalinity. Representative taxa included the
tolerant worms (Lumbricidae and
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