Toxicity of contaminants in lagoons and pannes of the Indiana Dunes National Lakeshore

Contaminants in water and sediments of lagoons and pannes were 2--90 times greater at sites adjacent to slag and coal piles than those at reference sites. One site (Lagoon-US5) had sediments with very high concentrations of toxic organics (e.g. naphthalene, phenanthrene, dibenzofuran). Although analyses indicated a gradient of contaminant concentration with distance from their sources, toxicity assays were somewhat equivocal. With the exception of less reproduction in Ceriodaphnia at one lagoon site (US3 = 0.55 of reference), survival of fathead minnows and reproduction in Ceriodaphnia in lagoon and panne waters varied independently of the contaminant concentration. In fact, there was better Ceriodaphnia reproduction in water from two contaminated sites (Lagoon-US5, Panne-WP1) than in water from reference sites. Fathead minnow survival, Ceriodaphnia survival, Ceriodaphnia reproduction, amphipod survival, and amphipod growth varied among sites in toxicity assays with sediments, 100% mortality of fatheads at Lagoon-US5, 100% mortality of Ceriodaphnia at Lagoon-US3, and less survival of fathead minnows at Lagoon-US3 indicate possible toxicity from contaminants in sediments at these sites. Of all organisms and end-points tested, Ceriodaphnia survival seemed to be most closely associated with concentrations of contaminants in lagoon water and sediments. Amphipod survival also varied with contaminants in sediments, however, survivalmore » in sediments of contaminated sites ranged only from 0.90--0.93 of reference sites. Although the results are not consistent among organisms, toxicity assays indicate that sediments from the lagoon site with the highest contaminants (Lagoon-US5) and possibly those from another contaminated lagoon site (Lagoon-US3) could be toxic to aquatic organisms. Water and sediments from contaminated panne sites do not appear to be toxic to aquatic test organisms.« less