U.S. Fish and Wildlife Service Region 2 Contaminants Program ENVIRONMENTAL CONTAMINANTS IN FISH AND WILDLIFE OF THE LOWER GILA RIVER, ARIZONA by 1 Kirke A. King, Brenda J. Andrews , 2 3 Cynthia T. Martinez , and William G. Kepner U.S. Fish and Wildlife Service Arizona Ecological Services Field Office 2321 W. Royal Palm Road, Suite 103 Phoenix, Arizona 85021 December 1997 ABSTRACT Levels and potential effects of pesticides and metals on fish and wildlife of the lower Gila River and associated agricultural drainage canals in Maricopa County, Arizona, were investigated in 1994-95. Residues of DDT, an insecticide that has been suspended from use in Arizona for 25 years, are still present in fish, turtles, and birds. DDT was detected in 86, 62, and 50% of the fish collected from Buckeye Canal, Gillespie Dam, and All enville, respectively. DDT was recovered in all turtles from Gillespie Dam, and in all black-crowned night-herons from Painted Rock. DDE residues in fish from the lower Gila River drainage were the highest in the United States associated with agriculturally applied pesticides. Although DDE residues declined over the past decade; current levels remain extremely high. DDE was present at concentrations known to impact biotic resources. Fish collected from agricultural drainage canals generally contained higher DDE residues than fish from the river. DDE residues were highest in common carp (Cyprinus carpio) from Buckeye Canal (11.17 p.g/g wet weight), an agricultural drain and tributary to the Gila River. The overall frequency of occurrence of organochlorine compounds is declining, however, as only 6 compounds were detected in samples collected in 1994-95 versus 16 recovered in samples collected from the same sites in 1985. Residues of all other pesticides and PCBs were below levels associated with adverse affects on fish and wildlife. Concentrations of 11 potentially toxic metals were detected in fish. Carp collected near Allenville had the second highest aluminum concentration ever recorded in Arizona. Copper exceeded the national 85th percentile in 31 of 48 samples. Because of its occurrence at relatively high levels and its propensity to interact with other compounds and elements, copper remains a contaminant of concern. Concentrations of most metals remained unchanged from 1985 to 1994-95. Spiny softshell turtles (Trionyx spiniferus) generally contained higher organochlorine and metal concentrations than fish. DDE and most metals were highest in turtles from the middle river sampling sites. Residues of DDE and chlordane declined by about one-half from 1985 to 1994-95. PCB, dieldrin, and DDT levels remained relatively constant over the past decade while copper, nickel, vanadium, and zinc concentrations declined. Levels of arsenic, mercury, and selenium in turtles collected in 1994-95 were statistically similar to concentrations in turtles collected in 1985. Whiptaillizards (Cnemodophorus spp.) collected from areas adjacent to the lower Gila River contained higher organochlorine residues than lizards collected from other Arizona locations. DDE and selenium exceeded toxic threshold levels that could be hazardous to avian predators that consume a large proportion of lizards in their diet. Mean mercury concentrations increased from 1985 to 1994-95 and were about 3- to 10-times higher in lizards collected in the Gila River basin than in lizards from other Arizona locations. DDE, mercury, and selenium pose a significant environmental challenge to black­ crowned night-herons (Nycticorax nycticorax) and possibly to other avian species nesting and wintering on the lower Gila River. All night-heron and two of four red-winged blackbird (Agelaifls phoeniceus) carcasses contained > 3.4 f.Lg/g wet weight DDE; the level associated with impaired reproduction. One-half of the blackbird carcasses contained sufficiently high DDE residues to represent a hazard to predatory birds that regularly feed on blackbirds. Mercury concentrations in five of six night-heron livers approached or exceeded the toxic threshold and the maximum concentration, 28.07 l'g/g dry weight, was 4.5-times higher than the toxic threshold. Selenium concentrations in night-heron livers (13 - 18 f.Lg/g dry weight) indicate that adults are not at risk of selenium intoxication, but selenium impacts on reproduction are possible. , Project No. 22410-l130-2F30 1 Present address: U.S. Fish and Wildlife Service, Cibola National Wildlife Refuge, Rt. 2, Box 138, Cibola, AZ 85328 2 Present address: U.S. Fish and Wildlife Service, 1500 N. Decatur #1, Las Vegas, NV 89108 3 Present address: U.S. Environmental Protection Agency, National Exposure Research Laboratory, P.O. Box 93478, Las Vegas, NV 89193-3478 TABLE OF CONTENTS Page 1. LIST OF TABLES . v 2. UST OF FIGURES ..................................... vi 3. INTRODUCTION . 1 4. STUDY AREA ........................................ 3 5. METHODS . 3 Sample collections . 3 Chemical analysis . 5 Statistical an;Uysis . 5 6. RESULTS . 7 FISH ............................................ 7 Organochlorines in whole fish . 7 Organochlorines in fillets . 9 Metals in whole fish . 9 Metals in fish fillets . 16 TURTLES ......................................... 19 Organochlorines in turtles . 19 Metals in turtles . 21 LIZARDS ......................................... 23 Organochlorines in lizards . 23 Metals in lizards . 23 BIRDS ........................................... 24 Organochlorines in birds . 24 Metals in birds . 24 7. DISCUSSION ........................................ 26 FISH ..........................· .................. 26 Organochlorines in whole fish . 26 Metals in whole fish ................................. 28 TURTLES ......................................... 31 Organochlorines in turtles . 31 Metals in turtles . 32 LIZARDS ......................................... 32 Organochlorines in lizards . 32 Metals in lizards . 32 iii BIRDS ........................................... 33 Organochlorines in birds . 34 Metals in birds . 35 HUMAN HEALTH CONCERNS , .......................... 37 8. CONCLUSIONS .........................•............. 38 9. RECOMMENDATIONS .................................. 39 10. ACKNOWLEDGEMENTS ................................ 40 11. LITERATURE CITED . 41 12. TABLES ........................................... 49 13. APPENDIX .......................................... 67 ' iv LIST OF TABLES Table 1. Organochlorine residues in individual whole body fish collected from the lower Gila River, Arizona, 1994-95 ...................... 49 2. Organochlorine compounds in common carp collected from the lower Gila River, Arizona, 1994-95: a comparison among collection sites ......... 51 3. Organochlorine compounds in fish fillets collected from the lower Gila River, Arizona, 1994-95 ................................ 52 4. Metals in individual whole body fish collected from the lower Gila River, Arizona, 1994-95 . 53 5. Metals in common carp collected from the lower Gila River, Arizona, 1994-95: a comparison among collection sites .................... 6. Metals in common carp and largemouth bass fillet samples collected from the lower Gila River, Arizona, 1994-95 .................... 7. Organochlorine residues in individual softshell turtles collected from the lower Gila River, Arizona, 1994-95 ...................... 58 8. Geometric mean concentrations of organochlorine compounds in softshell turtles collected from the lower Gila River, Arizona 1994-95 ....... 59 9. Trace element concentrations in individual whole body softshell turtles collected from the lower Gila River, Arizona, 1994-95 . 60 10. Metals in softshell turtles collected from the lower Gila River, Arizona, 1994-95: a comparison among collection sites ...................... 61 11. Organochlorine compounds in whiptail lizards collected from the lower Gila River, Arizona, 1985 and 1994-95 ............................. 62 12. Metals in whiptaillizards collected from the lower Gila River, Arizona, 1985 and 1994-95. ..................................... 63 13. Organochlorine residues in bird carcasses collected from the lower Gila River, Arizona, 1994-95 ................................... 64 14. Metals in whole body red-winged blackbirds collected from the lower Gila River, Arizona, 1985 and 1994-95 .......................... 65 15. Metals in black-crowned night-heron and red-winged blackbird whole boqy and liver samples collected from the lower Gila River, Arizona, 1994-95 . 66 v LIST OF FIGURES Figure 1. Lower Gila River, Arizona sample collection sites 1985 and 1994-95 ......... 4 2. Geometric mean DDE residues in carp, lower Gila River, Arizona, 1985 and 1994-95 . 8 3. Geometric mean arsenic concentrations in carp, lower Gila River, Arizona, 1985 and 1994-95 ................................. 11 4. Geometric mean copper concentrations in carp, lower Gila River, Arizona, 1985 and 1994-95 ................................. 13 5. Geometric mean mercury concentrations in carp, lower Gila River, Arizona, 1985 and 1994-95 ................................. 14 6. Geometric mean selenium concentrations in carp, lower Gila River, Arizona, 1985 and 1994-95 ................................. 15 7. Geometric mean vanadium concentrations in carp, lower Gila River, Arizona, 1985 and 1994-95 ................................. 17 8. Geometric mean zinc concentrations in carp, lower Gila River, Arizona, 1985 and 1994-95 ....................................... 18 9. Geometric mean DDE residues in softshell turtles, lower Gila River, Arizona, 1985 and 1994-95 . 20 vi INTRODUCTION