9480

• UCREFRP Catalog Number: 9480
• Author: Mueller, G.
• Title: Establishment of a Fish Community in the Hayden-Rhodes and Salt-Gila Aqueducts, Arizona
• USFW Year: 1996
• USFW - Doc Type: North American Journal of Fisheries Management
• Copyright Material: YES

798
MUELLER
TABLE 1.-Densities and numbers of ichthyloplankton collected from the Hayden-Rhodes Aqueduct, Arizona, during
April-June 1987 and 1988. Sites are shown in Figure 1; N = number of samples, V = total sample volume.
Measure or Fish family
statistic Clupeidae Cyprinidae Centrarchidae Others Total
1987: Lake Havasu (N = 100; V = 4,439 m3)
Larvae/m3 0.81 0.11 0.21 <0.01 1.13
SD 1.65 0.35 0.23
Total number 3,577 494 925 40 5,036
Percent 72.4 9.5 17.4 0.7 100.0
1987: Bouse Hills (N = 128; V = 4,213 m3)
Larvae/m3 20.98a 0.71a 0.80a <0.01 22.48
SD 34.30 1.70 1.74
Total number 88,368 2,971 3,363 6 94,708
Percent 92.2 3.3 4.4 <0.1 100.0
1988: Lake Havasu (N = 68; V = 1,460 m3)
Larvae/m3 0.67 0.04 0.18 0.89
SD 0.89 0.16 0.24
Total number 848 39 213 1,100
Percent 77.1 3.5 19.4 100.0
1988: Bouse Hills (N = 78; V = 1,081 m3)
Larvae/m3 0.20 1.763 0.11 2.06
SD 0.27 3.49 0.16
Total number 208 1,644 99 1,953
Percent 10.7 84.2 5.1 100.0
1988: Little Harquahala (N = 50; V = 733 m3)
Larvae/m3 0.70a 0.49 0.07 1.27
SD 0.96 0.62 0.10
Total number 441 339 46 826
Percent 53.4 41.0 5.6 100.0
1988: Hassayampa (N = 46; V = 742 m3)
Larvae/m3 2.20a 0.23 0.02 2.45
SD 3.25 0.48 0.05
Total number 1,505 146 13 1,664
Percent 90.4 8.8 0.8 100.0
a Value significantly (P = X0.05) higher than upstream station, suggestive of spawning
Ichthyoplankton
Numerically, larval fish entrained from Lake
Havasu by the Lake Havasu Pumping Plant during
1987-1988 consisted of 72-77% clupeids, 17-
19% centrarchids, and 4-10% cyprinids (Table 1;
for species and scientific names, see Table 2).
These three families constituted 99% of the larvae
entrained from Lake Havasu; ictalurids and catos-
tomids represented less than 1%. Larval entrain-
ment peaked in May. No larval striped bass were
collected in either year, and only five eggs (0.001/
m3) were collected in 1987. Centrarchid larvae
first appeared in early April and maintained rela-
tively constant numbers through the sampling pe-
riod (Figure 2). Clupeid entrainment peaked in late
April or early May.
In 1987, 228 ichthyoplankton samples were col-
lected (Table 1), representing the filtering of 8,652
m3 of water. Collectively, 19,867 fish eggs and
99,744 fish larvae were collected. Larval fish den-
sities averaged 1.13 larvae/m3 at the Lake Havasu
Pumping Plant, compared with 22.48 larvae/m3
further downstream at the Bouse Hills Pumping
Plant (Table 1). Average densities of larval clu-
peids, cyprinids, and centrarchids were all higher
at Bouse Hill compared with the densities of larval
fish entering the canal system at the Lake Havasu
Pumping Plant. Clupeid abundance increased the
most, from 0.81 to 20.98 larvae/m3. Egg densities
decreased downstream, averaging 4.29 eggs/m3 at
Havasu and 0.33 eggs/m3 at Bouse Hills.
In 1988, 242 samples were collected (Table 1),
representing the filtering of 4,016 m3 of water. The
smaller sample volume reflects problems associ-
ated with suspended debris caused by higher op-
erational velocities. In all, 1,060 fish eggs and
20,543 larvae were collected. Larval densities in-
creased between Lake Havasu and Bouse Hills
(from 0.89 to 2.06 larvae/m3) and between Har-
quahala and Hassayampa (from 1.27 to 2.45 lar-