Datasets / Contamination in aquatics and sediment at Trinity River National Wildlife Refuge, Texas


Contamination in aquatics and sediment at Trinity River National Wildlife Refuge, Texas

Published By US Fish and Wildlife Service, Department of the Interior

Issued over 9 years ago

US
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Summary

Type of release
a one-off release of a single dataset

Data Licence
Not Applicable

Content Licence
Creative Commons CCZero

Verification
automatically awarded

Description

Located northeast of Houston in Liberty County, Texas, the Trinity River National Wildlife Refuge Refuge was established in January 1994, and soon thereafter Champion Lake was acquired as part of the Refuge. This 700 acre lake receives water from the Trinity River. The river drains the moderately industrialized Dallas Fort Worth, Texas metroplex, and flows southward for 250 miles 402 km through several small urban areas and ranch land. Prior contaminant investigations of sites upstream of the refuge indicated several organochlorine compounds and heavy metals which may pose a hazard to fish eating birds and human consumption of aquatic resources from Champion Lake Irwin 1988, Ulery and Brown 1994, and Moring 1997. On request of the Refuge Manager, in June, 2002, personnel from the U.S. Fish and Wildlife Service Service Ecological Services Field Office in Clear Lake, TX initiated an investigation to determine levels of contaminants in sediments and fish inhabiting Champion Lake on the Refuge and to assess risks to people that eat fish from Champion Lake. To accomplish this, tissue samples, consisting of fillet and whole body samples from largemouth bass Micropterus salmoides, channel catfish Ictalurus punctatus, blue catfish Ictalurus furcatus and white crappie Pomoxis annularis, edible portions of blue crab Callinectes sapidus, and sediment samples were collected from Champion Lake and analyzed for 29 organochlorine compounds and 19 heavy metals. Additionally, sediment samples were also analyzed for 44 polycyclic aromatic hydrocarbons PAHs. PCB, mercury, and dieldrin fish tissue concentrations showed exceedences of screening values. Exceedences of the recreational fisher PCB screening value 0.02 ppm were found in four out of five of the bass fillet samples, three out of five of the catfish fillet samples, and two out of five of the crappie fillet samples. All the remaining samples exceed the subsistence fisher PCB screening value 0.00245 ppm. Exceedences of the recreational fisher mercury screening value 0.4 ppm were found in one of the five crab samples and one of the five catfish fillet samples. All remaining samples exceed the subsistence fisher mercury screening value 0.049 ppm. The process detailed in USEPAs Guidance for Assessing Chemical Contamination Data for Use in Fish Advisories was followed in determining fish consumption recommendations. Results indicate that fish and crab from Champion Lake contain elevated levels of mercury and PCBs. The Service recommends taking a conservative approach based on these preliminary findings and posting a fish consumption guideline for blue crab, bass, catfish and crappie. Utilizing EPAs default assumptions it is recommended that individuals should restrict their consumption of crab to one eight ounce meal per month, largemouth bass to three eight ounce meals per month, and catfish and crappie to two eight ounce meals per mouth. These data are based on preliminary sampling. To more thoroughly assess risk, a creel survey should be conducted to examine species consumed and frequency of consumption. Further studies should be conducted involving the collection of fish, crawfish, avian eggs, and water samples to determine the extent and availability of mercury and PCBs to fish and other wildlife resources at the Refuge.