Dispersal and persistence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in a contaminated aquatic ecosystem, Bayou Meto, Arkansas

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:197537

Heckathorn, W D ^[1]; Johnson, J E ^[2]; Thompson, A L

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1. Fish and Wildlife Service, Sacramento, CA (United States)
2. National Biological Service, Fayetteville, AR (United States)

In 1991, sediment and fish samples were collected from Bayou Meto above and below the Vertac Chemical Corporation in Jacksonville, Arkansas. The purpose of this study was to: (1) assess present concentrations of dioxins in sediments and fishes of Bayou Meto; (2) compare the present concentrations and distribution of dioxins in Bayou Meto to concentrations found in previous studies; (3) examine the dispersion of TCOD from its point source; and (4) compare experimental theories on biomagnification with the field findings. The sediment and fish were collected from twelve sites on Bayou Meto, and two sites on Wattensaw Bayou. Concentrations of 2,3,7,8-TCDD were elevated in sediment and fish samples at levels sufficient to pose a threat to fish and wildlife resources. TCDD concentrations remained above background levels downstream, grading in a classic pattern of dispersion from a single point source. For all samples, the higher chlorinated congeners were orders of magnitude higher than the TCDD concentrations. The highest TCDD concentration in sediments and fishes were found immediately downstream from Rocky Branch at river km 250. TCDD concentrations in fish and sediment samples were elevated above background level to the furthest downstream sampling station at river km 36. However, TCDD levels in Bayou Meto sediments have declined over time by dispersion and sedimentation. Juvenile bluegills consistently contained 2.4 times more TCDD than did the smallmouth buffalo, and 6.2 times more TCDD than the largemouth bass. Bluegill samples at the sampling station below Rocky Branch were the only fish where concentrations exceeded those of the sediments. Fishes do not appear to biomagnify TCDD. TCDD body burdens of fishes appear to be determined primarily by lipid concentrations and secondarily by association to the sediments and diet.

• OSTI ID: 197537
• Report Number(s): CONF-9511137--; ISBN 1-880611-03-1
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ARKANSAS
BIOLOGICAL ACCUMULATION
CHEMICAL EFFLUENTS
DIOXIN
ECOLOGICAL CONCENTRATION
ESTUARIES
SEDIMENTS
WATER POLLUTION