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https://hdl.handle.net/11681/20505| Title: | Chronic sublethal effects of San Francisco Bay sediments on Nereis (Neanthes) arenaceodentata : effect of storage time on sediment toxicity |
| Authors: | Moore, David W. Dillon, T. M. (Tom M.) |
| Keywords: | San Francisco Bay Area (Calif.) Toxicity Contaminants Pollution Dredged material Dredging spoil Environmental effects Nereis arenaceodentata |
| Publisher: | Environmental Laboratory (U.S.) |
| Series/Report no.: | Miscellaneous Paper;D-94-2 |
| Abstract: | Abstract: This report was designed to address concerns regarding the effect of sediment storage time on toxicity. To this end, seven San Francisco Bay area sediments and a "clean" control sediment were evaluated in chronic sublethal tests with the marine polychaete worm Nereis (Neanthes) arenaceodentata. Juvenile worms (2 to 3 weeks postemergence) were exposed for 21 days. Test end points were survival and growth. Sediment toxicity was evaluated initially (within 30 days of collection) and at different points over time up to 2 years after collection. All San Francisco Bay area sediments were composites of several cores taken to project depth (38 ft (11.6 m) below mean low water mark) from a specific area. Reference sediments were collected from three potential in-bay disposal areas: on the mound at the Alcatraz disposal site, surrounding areas adjacent to the mound, the Bay Farm Borrow Pit in South Bay, and from an area outside the bay, Point Reyes (PRR). Project sediments were collected from three areas in Oakland Harbor: Oakland Inner Harbor (OI); Oakland Outer Harbor (OO) and from areas of OI known to be contaminated with metals and polyaromatic hydrocarbons, Oakland Contaminated (OC). The control sediment is used in our laboratory cultures of N. arenaceodentata and was collected from Sequim, WA. Mean percent survival of N. arenaceodentata was high (80 to 100 percent) in all sediments. Significant mortality was only observed in a single instance (i.e., 0-percent survival in OC sediment on Day 427) and may have been related to high levels of ammonia (mean total ammonia = 11 mg/L) measured in the overlying water. Mean total ammonia levels in the overlying water of Sequim Control, PRR, OO, and OC sediments showed a cyclical pattern with increasing storage time. Higher ammonia levels were measured in these sediments during tests initiated on Days 65, 427, and 740. Significant differences in growth rate over time were observed in tests with both the OI and OC sediment. In addition, the OC sediment showed a slight, but not statistically significant, trend towards increasing growth with storage time. |
| URI: | http://hdl.handle.net/11681/20505 |
| Appears in Collections: | Miscellaneous Paper |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| MP D-94-2.pdf | 9.12 MB | Adobe PDF |  View/Open |