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<br />57.1 <br /> <br />SAN JUAN RIVER BIOLOGICAL EFFECTS STUDIES <br />FISCAL YEAR 1997 PROJECT PROPOSAL <br /> <br />Background: <br /> <br />Limited analyses of water, sediment, and tissue collected from the San Juan River have shown the <br />presence of selenium and other inorganics and organics at concentrations that could potentially be <br />harmful to fish and wildlife. However, the biological significance of short-term (acute) or long-term <br />(chronic) exposure to these elevated inorganics and organics to threatened or endangered fish in the <br />San Juan River is unknown. Infomiation is needed to identifY waterborne and dietary contaminants <br />that may adversely affect the recovery of threatened or endangered fish. Acute tests should be <br />conducted with individual inorganics and organics and with mixtures of inorganics and organics in <br />their environmental ratios found at potentially harmful sites along the San Juan River used as nursery <br />areas by endangered or threatened larval fish or staging areas by adults. Those inorganics and <br />organics that show high toxicity in acute toxicity tests relative to their environmental concentrations <br />should be further evaluated in long-term tests to determine sublethal effects and to delineate the <br />relation between whole-body burdens and other biological effects. Long-term tests are needed with <br />endangered adult fish to assess the potential for inorganic and organic contaminants to adversely <br />affect reproduction. <br /> <br />Objectives: <br /> <br />Determine the chronic effects on reproduction of adult Colorado squawfish (,etychocheilus lucius) of <br />combined waterborne exposure toa mixture of in organics and a dietary exposure to organic <br />selenium. <br /> <br />Methods: <br /> <br />A long-term chronic toxicity test will be conducted according to standard methods, except that the <br />water quality will simulate that in the San Juan River. The test species will be adult Colorado <br />squawfish acquired from Dexter National Fish Hatchery & Technology Center, NM. The test will be <br />conducted for 180 days with fish exposed to dietary (0,5, & 10 f.J-g/g) and waterborne (0 & 5 <br />f.J-g/liter) selenium. The study will include three replicates each of a control and five treatments. <br />After 180 days of exposure to dietary and waterborne selenium, adults will be induced to spawn and <br />the resulting hatch larvae exposed to dietary and waterborne selenium for 30 days post-hatch. Tissue <br />residues of selenium in adults will be monitored before spawning and for 60 days after spawning <br />when adults are held in clean water and fed control diet to determine depuration rates. <br /> <br />The water temperature and photoperiod will simulate conditions in the San Juan River. The water <br />quality in chronic toxicity test will simulate that in the San Juan River in terms of the major cations <br />and anions at Shiprock, New Mexico: hardness ISO mgIL, alkalinity 89 mgIL, Ca 43 mgIL, Mg 9.2 <br />mgIL, Na 22 mgIL, C15.9 mgIL, S04 89 mgIL (Beal, L.V., and R.L. Gold. 1986. Water Resources <br />Data New Mexico Water Year 1986. USGS Water Data Report NM-86-1, Albuquerque, NM. <br />Station ID 09368000, 11/05/85, Shiprock, NM). <br /> <br />34 <br />