WSP02811

• File Number: 8200.766
• Description: Gunnison River General
• State: CO
• Basin: Gunnison
• Water Division: 4
• Date: 1/1/1991
• Author: USGS
• Title: Reconnaissance Investigation of Water Quality-Bottom Sediment-and Biota Associated with Irrigation Drainage - Gunnison and Uncompahgre River Basins and Sweitzer Lake - West Central Colorado
• Water Supply Pro - Doc Type: Report/Study

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Table J4.--Range of concentrations of selected trace ele~nts in invertebrate
~ aqu.tic plant samples

IConcentrations are in micrograms per gram dry weight; n. number of samples; NO, not detected;
aq., aquatic; iov., invertebrate; --, no datal

Trace
element

Gunnison River below
Gunnison Tunnel
(Site 2)
Aq. iov. Aq. plant
n= I 0=2

Gunnison River
at Delta
(Site 3)
Aq. iov. Aq. plant
0=2 n= I

Uncompahgre River
at Colona
(Site 4)
Aq. iov. Aq. p-lanl
0=2 0=2

Sweitzer Lake
(Site 7)
Aq. iov. Aq. plant
0=2 n=lt

Arsenic
Copper
Hercury
Selenium
Zinc

2.6
28.6
.20
1.2
85. I

3.0-4.2
NO
NO
I. 2-2.2
87. 9-114

2.8-7.5
NO-92.7
NO-.24
5.6-6.8
92.3-96.4

6.7
NO
.34
.70
70.5

3.1-6.0
56.1-76.4
.04-.14
3.1-4.7
386-433

.41-12.0
NO
NO
7.9-12.8
10.8-44.5

11.0-13.0
20.0-62.5
.02-.03
.49-1. 4
124-231

]] .5-12.0
26.4-50.0
NO-.30
26.7-29.8
126-202

Trace
element

Uncompahgre River
at Delta
(Sile 9)
Aq. inv. Aq. plant.
0=1 0=2

Gunnison River at Escalante
St.te Wildlife Area
(Site 10)
Aq. inv. Aq. plant
n= I n=2

Happy Canyon, Spring,
and Dry Creek&:
(Sites 12, 13. 14)
Aq. inv. Aq. plant
n= I n=5

Arsenic
Coppe r
Mercury
SeJeniWll
Zinc

2.8
117
NO
4.1
77 .4

3.6-9.6
1ID-22.5
NO-.38
I. 7-4.4
88.2-425

2.3
77 .6
NO
4.8
68.3

3.6-7.8
17.2-44.9
NO
I. 7-3.4
76.1-88.2

9. I
lID
NO
2.8
119

2.3-9.0
}ffi-21.9
NO
N'D-l.0
49.0-96.3

muscle samples collected in March 1989 (table 23) was about 28 ~g/g, or about
5.9 ~g/g wet weight (average percent moisture was about 79 percent). One large
catfish provided about 547 g of filet meat (from both sides); that filet meat
would contain about 3,230 ~g (5.9 ~g/g times 547 g) of selenium. Human con-
sumption of 3 ounces of that filet meat would result in consumption of about
502 ~g of selenium. Levander (1984) suggested a maximum daily selenium intake
of 500 ~g for adults and 200 ~g for children. Shamberger (1981) suggested a
maximum average daily intake of 200 ~g of selenium for adults.

Bird samples also had relatively large concentrations of selenium
(figs. 18 and 19; table 15), which may be expected because of the selenium
concentrations in avian food items. Selenium concentrations in invertebrate
and aquatic plant samples exceeded the concentration range of 4 to 8 ~g/g dry
weight of selenium (as selenomethionine) that Heinz and others (1989) reported
as causing reproductive impairment for mallards. However, Smith and others
(1988) reported that black-crowned night herons were less sensitive than
mallards to the toxic effects of selenium, and there was no difference in
hatching success between birds fed control diets and 10 ~g/g of selenium (as
selenomethionine) diets.

Western grebe livers had larger selenium concentrations (about 72 and
84 ~g/g dry weight) than livers of other bird species collected at Sweitzer
Lake (tables 15 and 23). These concentrations are in the range of selenium
concentrations in bird livers from Kesterson National Wildlife Refuge
(Ohlendorf and others, 1986). Fish are an important dietary component for
western grebes, which probably accounts for the large selenium concentrations
in the western grebe livers and the eared grebe whole-body sample (table 23).
Also, the two western grebes may have been at Sweitzer Lake for more than
2 months when they were collected in July. Avian livers with more than
20 ~g/g wet weight (about 69 ~g/g dry weight) for selenium indicated significant
exposure to selenium (G.H. Heinz, U.S. Fish and Wildlife Service, oral commun.,
1990), and could be considered as an indication of a possible health threat to
the bird.

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