7821

• UCREFRP Catalog Number: 7821
• Author: Hamilton, S. J., et al.
• Title: Evaluation Of Toxicity To Larval Razorback Sucker Of Selenium-Laden Food Organisms From Ouray NWR On The Green River, Utah.
• USFW Year: 1996.
• USFW - Doc Type: \
• Copyright Material: NO

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substantially (Tables 2 and 3). Conductivity was lowest at S 1 and generally three times
higher at SR and NR. Sites S3 and S4 were close to characteristics at Sl, whereas S5 was
similar to SR and NR. Chlorides and sulfates in particular showed wide variation between
sites, especially study 3 where chlorides were 12 to 13-fold higher and sulfates 4 to 5-fold
higher in SR and NR than in Sl (Table 2).

Inorganic residues

Selenium concentrations in water at the six sites also varied greatly (Table 4).
Reference water from Sl was consistently low in selenium concentration (< 1.1 J,tg/L) during
the four studies. Consequently, waterborne selenium in reference water used in all exposure
beakers probably did not contribute to adverse effects observed with larval razorback sucker.
Selenium concentrations in water from other sites were higher than the reference site.
Measured selenium concentrations were low at S3 and S4 (0.3 - 0.8 J,tg/L), slightly higher at
S5 (0.6 - 3.1 J,tg/L), and substantially higher at SR (14-21 J,tg/L) and NR (57-107 J,tg/L).

Selenium concentrations in zooplankton from the S 1 reference site were relatively low
and ranged from 2.3 to 3.5 /-Lg/g (Table 5). Concentrations were slightly higher in S3 and
S4 (2.4 - 6.7 J,tg/g), substantially elevated at S5 (12 - 26 J,tg/g), and extremely high at SR
and NR (44 - 96 J,tg/ g). Selenium concentrations decreased in zooplankton over time in sites
SI, S3, S4, and S5 probably due in large part to the flooding of these ponds with water from
the Green River. Waterborne concentrations of selenium at these sites were uniformly low
(Table 4) and did not change as much as selenium concentrations in zooplankton (Table 5).
Selenium concentrations in aquatic macroinvertebrates were elevated similar to those in
zooplankton (Table 6). Concentrations of selenium in macro invertebrates were lowest at
sites SI, S3, and S4, intermediate at S5, and highest at SR and NR.

Concentrations in water of only four elements out of 32 measured by ICAP showed a
pattern of elevation across sites similar to selenium (Table 7). Concentrations of boron,
lithium, sodium, and strontium were lowest in Sl, intermediate in S3, S4, and S5, and
highest in SR and NR, whereas 28 other elements had similar concentrations at the six sites.
The analytical limits of detection are usually high in ICAP analyses and the analysis is
typically conducted to detect relatively elevated concentrations of elements. The leAP
analysis showed selenium was elevated at SR and NR, but below detection at sites Sl, S3,
S4, and S5.

Concentrations in zooplankton of only two elements, strontium and zinc, out of 31
measured by ICAP showed a pattern of elevation across sites similar to selenium (Table 8).
Several elements had higher concentrations in zooplankton from SI than other sites: arsenic
was 4 times higher than S4, cadmium 0.5-5 higher, copper 0.5-2 higher except for S4, nickel
2-7 higher, and lead 2-3 higher. Chromium was elevated in NR, vanadium in S3 and NR,
and zinc elevated in SR and NR. Selenium was detected in SR and NR, but not at other
sites, because of the relatively high limit of detection (9 J,tg/g).

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