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<br />SIMULATING IRRIGATION WATER TOXICITY 57
<br />
<br />TABLE VII. M.ean (SE) of fish activity (grid crossings/min) and critical swimming speed (cm/s)
<br />of razorback sucker and bonytall exposed to a mixture of nine elements simulating
<br />Ashley Creek, Utah, In a reconstituted water representing the Green River
<br />
<br /> Activity Critical swimming speed
<br />Species and treatment Day 30 Day 60 Day 90
<br />Razorback sucker
<br />Control 23(8) 34.5(0.8) 33.9( 1.0)
<br />IX' 25(8) 32.0(1.1) 29.1(1.6)
<br />2X 29(10) 30.2(1.0) 28.8(1.3)
<br />4X 27(13) 33.6(0.8) 31.5(1.5)
<br />8X 107(12)**b 9.6( 1.5)* * 15.7(1.7)**
<br />16X 32(5) c
<br />Bonytail
<br />Control 90(12) 38.9(1.2) 39.4(1.2)
<br />IX 40(5)* 38.8( 1.5) 38.7( 1.2)
<br />2X 31(8)** 38.2(0.8) 36.4(0.9)
<br />4X 150(26) 36.5( 1.0) 36.4(0.9)
<br />8X 114(17) 30.6(1.4)** 32.20.1)**
<br />16X 144(9) 20.9(1.7)** 22.6(1.3)**
<br />
<br />· IX = mixture of 2 ~g/L As, 630 ~g/L B, 10 ~g/L Cu, 5 ~g/L Mo, 51 ~g/L Se +6, 8 ~g/L Se H, 33 ~g/L U, 2
<br />~g/L V, and 20 ~g/L Zn.
<br />b Asterisks indicate significant difference from the control within a column (ANOV A; * P " 0.10, * * P .. 0.05).
<br />C No fish available.
<br />
<br />that this mixture posed a high hazard to the fish and
<br />probably could cause chronic effects in these fish at
<br />environmental concentrations.
<br />Tests with individual inorganics and the three en-
<br />dangered fish have found that some inorganics may
<br />pose a hazard to endangered fishes in the Green River.
<br />Hamilton (1995) reported moderate hazard ratios for
<br />boron, selenate, selenite, and zinc, and low hazard
<br />ratios for uranium and vanadium. Buhl (1997) reported
<br />low hazards for cadmium, chromium, lead, and mer-
<br />cury. Buhl and Hamilton (1996) reported a high hazard
<br />for copper and zinc. However, the highest reported
<br />hazards to these endangered fish were from the mix-
<br />tures of inorganics simulating Ashley Creek and Stew-
<br />art Lake outlet (Buhl and Hamilton, 1996).
<br />The toxicity of inorganic mixtures simulating condi-
<br />tions in other waters receiving irrigation drainage have
<br />also been found to pose hazards to fish in western
<br />rivers. In tests with Colorado squawfish and razorback
<br />sucker and a water simulating the San Juan River of
<br />New Mexico, a high hazard was reported for copper
<br />and five environmental mixtures of inorganics (Ham-
<br />ilton and Buhl, 1997a). In tests with flannelmouth
<br />sucker (Catostomus latipinnis), a Species of Concern
<br />(formerly Category 2 species listed by the U.S. Fish and
<br />Wildlife Service), and a water quality simulating the
<br />San Juan River, the highest hazards were for copper
<br />and four- environmental mixtures of inorganics, with
<br />moderate hazards for zinc and a fifth inorganic mix-
<br />ture, and low for arsenic, boron, molybdenum, selenate,
<br />
<br />selenite, uranium, and vanadium (Hamilton and Buhl,
<br />1997b).
<br />
<br />Behavior
<br />
<br />A variety of behavioral tests have been used to discern
<br />the effects of inorganic contaminants on fish behavior
<br />including cough rate, avoidance reactions, predation
<br />avoidance, feeding behavior, learning, social interac-
<br />tions such as schooling, and locomotion behaviors such
<br />as swimming performance (Atchison et aI., 1987; Little
<br />and Finger, 1990; Little et aI., 1993). Several of these
<br />altered behaviors were observed in the present study at
<br />exposure concentrations similar to those reported by
<br />others. Temporary feeding inhibition has been reported
<br />for rainbow trout (Oncorhynchus mykiss) exposed to
<br />100 to 300 /-Lg/L of copper, but feeding returned to
<br />control levels in 15 days (Lett et aI., 1976). Sandhein-
<br />rich and Atchison (1989) also reported reduced forag-
<br />ing behavior in bluegill (Lepomis macrochirus) exposed
<br />31 p.g/L of copper, which they concluded would result
<br />in reduced growth of wild fish and altered prey commu-
<br />nities. Reduced feeding has also been reported in At-
<br />lantic salmon (Salmo salad parr exposed to zinc con-
<br />centrations as low as 420 p.g/L initially, but even at
<br />1000 p.g/L, food intake returned to control levels
<br />within 10 to 20 days (Farmer et aI., 1979). These
<br />concentrations of copper and zinc are equal to or
<br />greater than the concentrations incorporated in the
<br />mixture of inorganics tested. Contaminants have been
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