PM08 Sediment Quality Assessment
Exhibit Hall
8:00 AM - Monday
(PM109) Predicting toxicity of sediments to UV exposure using SQGs.
Kemble, Nile1, Ingersoll, Chris1, Ivey, Chris1, MacDonald, Don2, Sparks, Daniel, 1 Columbia Environmental Research Center, USGS, Columbia, MO, USA2 MacDonald Environmental Sciences Ltd, Nanaimo, BC, Canada
ABSTRACT- The toxicity of sediment samples from Roxana Marsh and the West Branch of the Grand Calumet River located in Northwestern Indiana were evaluated using 28-d whole-sediment toxicity tests and subsequent ultraviolet (UV) exposures with the amphipod Hyalella azteca. Surface sediment samples or core samples were collected from 20 locations with in Roxana Marsh and subdivided into 64 samples, while surface sediment samples or core samples were collected from 38 locations along the West Branch of the Grand Calumet and subdivided into a total of 43 samples. At the end of the whole-sediment exposures survival of amphipods was significantly reduced in 8 of the Roxana Marsh samples (13%) and length of amphipods was significantly reduced compared to the control in 3 of the 64 samples. At the end of the whole-sediment exposures survival of amphipod in the West Branch samples was significantly reduced in 20 of the 43 samples (47%) and length on Day 28 was significantly reduced relative to the control sediment in 1 of the 33 samples (3%). Preliminary chemistry data indicated that PAHs were elevated in several of these samples. Therefore, we subsequently exposed amphipods from these sediments to UV lighting. Subsequent exposure of surviving amphipods to UV resulted in >20% mortality in 15 of 19 (79%) of the Roxana Marsh samples and 14 of 41 (34%) of the West Branch samples. A total of 58% of these samples from Roxana Marsh and 7% of these samples from the West Branch were only toxic after subsequent exposure to UV. Evaluations of the relationship between sediment chemistry and UV toxicity are on going. Results of this study will be used to make restoration decisions in the area as part of a natural resource damage assessment and restoration project.
Key words: Core samples, sediment, photo-induced, Hyalella azteca