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The State of Natural and Cultural Resources in the Colorado River Ecosystem:

JUNE 30, 1999 DRAFT REPORT
Grand Canyon Monitoring and Research Center
Flagstaff, AZ 86001
Updated: 30 June 1999

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Aquatic Biological Resources

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Aquatic Biological Resources

Aquatic Foodbase: Glen Canyon Reach

Figure AB1.1:

Figure AB1.1 : Average ash-free dry mass (AFDM, g C/m2 + 1 se) of Cladophora glomerata from benthos collections at Lees Ferry cobble bar, January 1991 - June 1998 (Graph courtesy of Shannon et al.). Updated 9 June 1999.

Figure AB1.2:

Figure AB1.2: Average ash-free dry mass (AFDM, g C/m2 + 1 se) of macroinvertebrates from benthos collections at Lees Ferry cobble bar, January 1991 - June 1998 (Graph courtesy of Shannon et al.). Updated 9 June 1999.

Figure AB1.3:

Figure AB1.3: Average ash-free dry mass (AFDM, g C/m3 + 1 se) of Cladophora from drift collections at Lees Ferry cobble bar, September 1993 - June 1998 (Graph courtesy of Shannon et al.). Updated 9 June 1999.

Figure AB1.4:

Figure AB1.4: Density of macroinvertebrates ((no./m2) x 1000)) in the Glen Canyon Reach, 1993-1997 (Arizona Game and Fish Department). Variance data not presently reported. Updated 1 July 1998.

Fig. AB1.5:

 Fig. AB1.5: Average ash-free dry mass (AFDM, g C/m2 + 1 se) of Cladophora from benthos collections at 205 mile cobble bar, January 1991 - June 1998 (Graph courtesy of Shannon et al.). Updated 9 June 1999.

Fig. AB1.6:

Fig. AB1.6: Average ash-free dry mass (AFDM, g C/m3 + 1 se) of macroinvertebrates from drift collections at 205 mile cobble bar, near the downstream end of Grand Canyon. September 1993 - June 1998 (Graph courtesy of Shannon et al.). Updated 9 June 1999.

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Aquatic Habitat

Fig.AB2.1:

Fig.AB2.1: The number of backwaters (return current channels, shoreline embayments, and tributary mouths) between Lees Ferry and Diamond Creek, 1995-1997. Numbers represent discharge levels associated with backwater measurements. For example, 8k = 8,000 cfs. These data indicate that the number of backwaters available at a flow of 8,000 cfs has increased during Interim Flows and ROD flows (1991-1998). Draft data from Stevens and Hoffnagle (pers. comm.) updated 23 June 1999.

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Native Fish

Endangered Humpback Chub

(CYPRINIDAE: Gila cypha)

Hyperlink to Species of Concern, 23 June 1999.

Endangered Razorback Sucker

(CATOSTOMIDAE: Xyrauchen texanus)

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Other Native Fish Species:

Flannelmouth Sucker

CATASTOMIDAE: Catostomus latipinnis

Figure AB3.1: 1/2 Figure AB3.1: 2/2

Figure AB3.1: Catch per unit of effort of flannelmouth sucker in the Glen Canyon reach, 1992-1998 (Ted McKinney AGFD, unpublished data). Updated 9 June 1999. CPUE is a standardized metric of sampling for fish based on the amount of time spent fishing with a particular suite of gear types.

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BLUEHEAD SUCKER

CATOSTOMIDAE: Catostomus discobolus

Fig. AB3.2:

Fig. AB3.2: Data not presently available, 30 June 1999.

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SPECKLED DACE

CYPRINIDAE: Rhinichthys osculus

Fig. AB3.3:

Fig. AB3.3: Data not presently available, 30 June 1999.

Speckled Dace Species Account

Little synthesis of previously collected data has been attempted for speckled dace in Grand Canyon. This is the most common native fish species in the tributaries. Little synthesis has been attempted on the large amount of data available on population size, distribution, reproductive success, movement, genetics of several potential subspecies, or survival of this species. Because of its widespread distribution and abundance, it may serve as a regional indicator species of ecological health of the various Grand Canyon fish habitats if it can be demonstrated that speckled dace share habitats with other fish species.

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Non-Native Fish:

Rainbow Trout

SALMONIDAE: Oncorhynchus mykiss

Trout in the Glen Canyon Reach

Figure AB4.1:

Figure AB4.1: Trout condition factor ((length3/weight)x10000) in the Glen Canyon reach, 1984-1998 (data courtesy of the Arizona Game and Fish Department; updated 10 June 1999). See Figs. AB1.1 and AB1.2 for foodbase changes from 1995-1998.

Fig. AB4.2:

Fig. AB4.2: Rainbow trout catch per unit of effort by size class in the Glen Canyon Reach, 1991-1998 (data courtesy of the Arizona Game and Fish Department; updated 10 June 1999).

Fig. AB4.3:

Fig. AB4.3: Proportional stock density (the proportion of fish over 12 inches of quality size (16 inches) to anglers) in the Glen Canyon Reach, 1992-1997 (data courtesy of the Arizona Game and Fish Department; updated 1 July 1998).

Fig. AB4.4:

Fig. AB4.4: Angler catch rates compared with angler hours and rates of stocking in the Glen Canyon reach, 1984-1998 (data courtesy of the Arizona Game and Fish Department; updated 1 July 1998).

Fig. AB4.5 :

Fig. AB4.5 : Relative volume (volume/ total length of fish) of macroinvertebrates in trout gut contents in the Glen Canyon Reach, 1992-1997 (data courtesy of the Arizona Game and Fish Department; updated 1 July 1998).

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OTHER NON-NATIVE FISH SPECIES

Fig. AB5.1: Analyses underway, 10 June 1999.

Aquatic Biological Resources Monitoring Projects

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