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Preliminary Assessment of Contaminants and Potential Effects to Fish of the Truckee River, Nevada

Written By
Damian K. Higgins, Peter L. Tuttle, and J. Scott Foote
U.S. Fish and Wildlife Service
Nevada Fish and Wildlife Office

Environmental Contaminants Program
Off-Refuge Investigations Sub-Activity
FFS # 1130-1F35

January 2006

Previous investigations by U.S. Geological Survey (USGS) and others reported elevated concentrations of a variety of metals and polycyclic aromatic hydrocarbons (PAH) in Truckee River sediment collected in and downstream of the Reno-Sparks metropolitan area in Nevada in 1998. USGS scientists also documented elevated contaminant concentrations in fish and aquatic invertebrates which exceeded published biological effects criteria. In 1999 U.S. Fish and Wildlife Service (Service) biologists also noted a higher incidence of lesions, hemorrhagic septicemia, and external parasites in fish collected in this same reach. Therefore, the Service initiated a synoptic investigation in 2002 to determine if contaminants are affecting or have the potential to affect fish health, survival, or reproductive potential in the lower Truckee River. Specific Service objectives included: 1) evaluation of fish abundance and community structure; 2) assessment of the external condition of fish; 3) detailed evaluation of salmonid health (i.e., internal/external condition, histology, cytology, disease, and parasites); 4) characterization of fish contaminant exposure and accumulation; and 5) screening for indicators of endocrine disruption.

Fish were collected from 5 sampling sites on the Truckee River from Verdi, Nevada to its terminus near the Marble Bluff Dam at Pyramid Lake. Abundance and community structure values (species evenness and Index of Biotic Integrity) declined in a downstream fashion with notable reductions occurring at the Lockwood and Marble Bluff sample sites which were likely a result of cumulative effects of urbanization, loss of riparian cover, reduced flows, increased water temperature, as well as contaminants. Condition of brown trout and mountain/Tahoe suckers were significantly reduced at downstream sites. High percentages of external anomalies were also observed at sampling sites downstream of the Reno-Sparks urban area and ranged from 11% at Marble Bluff to a maximum of 43% at Lockwood. These anomalies were also likely the result of non-point sources, sewage effluent discharges, and reduced flows.

Evaluations of salmonid health revealed no significant issues with regards to organosomatic assays, blood chemistry, microbiological assessment, and histological evaluation from each sampling site. However, some data indicated suspected infections of bacterial kidney disease and other bacterial-type infections. However, these infections were not expressive enough or had detrimental impacts to those fish.

To assess contaminant exposure and accumulation, five to seven trout of appropriate size (? 200 mm) were randomly selected from sampling sites and were analyzed for polycyclic aromatic hydrocarbon metabolites in bile and concentrations of metals or trace elements in whole fish. Bile data revealed fish were being exposed to elevated concentrations of naphthalene and phenanthrene in the Reno-Sparks area. These concentrations, which were likely the result of urban run-off sources, exceeded criteria considered as contaminated. Whole fish data revealed concentrations of aluminum, barium, iron, and manganese were highest in rainbow trout compared to brown trout. Mercury concentrations in brown trout did not exceed water quality standards established by the Pyramid Lake Paiute Tribe. Concentrations of aluminum and barium in whole fish were highest above Reno and were likely the result of geochemical interactions of stream water with specific bedrock types. However, none of these concentrations exceeded known adverse biological effects. Concentrations of arsenic, mercury, and selenium in whole fish were highest at the Tracy sampling site located below the Reno-Sparks urban area. The sources of uptake for these constituents originate mostly from geothermal springs, historic mine wastes, irrigation, and tertiary-treated sewage effluent within the Steamboat Creek drainage. Arsenic and selenium concentrations did not exceed known adverse biological effects. Mercury concentrations in trout downstream of the Reno-Sparks urban area did not exceed avian dietary effects, fish consumption guidelines, and water quality standards established by the Pyramid Lake Paiute Tribe.

Several studies have associated municipal waste water discharges with endocrine system effects in fish. Because treated municipal waste water represents a significant component of flows in the lower Truckee River, blood plasma was collected to screen for indicators of endocrine disruption in trout. Vitellogenin (VTG) concentrations were detected in two males downstream of the Reno-sparks urban area. Male fish do not normally produce VTG, but the hepatic estrogen receptor and the gene that encodes for VTG is still present. The result is that when male fish are exposed to estrogenic compounds, VTG production can be induced. Also, all adult males in the fish health assessment had no mature testes at all sites. The presence of VTG in the two males combined with the organosomatic data provides some evidence of potential endocrine disruption in individual trout. However, additional research is needed to assess which endocrine disrupting compounds may be present in the Truckee River, and the extent to which these compounds may be affecting fish populations.

The long-term health and reproductive potential of fish in the Truckee River will be increasingly affected as the Reno-Sparks urban area continues to expand. Restoration of river function and augmentation of wetlands within the floodplain would assist in attenuating contributions of contaminants from various point and non-point sources. Improvements in sewage effluent discharges and effective urban planning can also assist to reduce both point and non-point sources of some contaminants. Without addressing these issues, these point and non-point sources of contaminants will present significant challenges to maintaining a healthy fishery and prevent long-term restoration efforts of Lahontan cutthroat trout (Oncorhynchus clarki henshawi) in the Truckee River.

Written in cooperation with

The authors acknowledge members of the U.S. Fish and Wildlife Service, U.S. Geological Survey, Nevada Department of Wildlife, Pyramid Lake Paiute Tribe and University of Nevada, Reno for providing ideas and information on fish and water-quality issues and for participating in this study. Members of those organizations who participated in data collection and provided technical assistance for this study include:

U.S. Fish and Wildlife Service
William Cowan, Jody Fraser, Rick Harmon, Chad Mellison, Bridget Nielsen, Stan Wiemeyer

U.S. Geological Survey
Timothy S. Gross, Angela Paul, Timothy Rowe, Karen A. Thomas

Nevada Department of Wildlife
Kim Tisdale

Pyramid Lake Paiute Tribe
Beverly Harry, Dan Mosley, Nancy Vucinich

University of Nevada, Reno
Sudeep Chandra, Ph.D, Laurel Saito, Ph.D

higgins_lower_truckee_river_2006.pdf2.29 MB