Surface sediment samples (0-5 cm) from 5 tidal salt marshes along the coast in California, USA were analyzed to investigate the occurrence and anthropogenic input of trace metals. Among study areas, Stege Marsh located in the central San Francisco Bay was the most contaminated marsh. Concentrations of metals in Stege Marsh sediments were higher than San Francisco Bay ambient levels. Zinc (55.3-744 μg g-1) was the most abundant trace metal and was followed by lead (26.6-273 μg g-1). Aluminum normalized enrichment factors revealed that lead was the most anthropogenically impacted metal in all marshes. Enrichment factors of lead in Stege Marsh ranged from 8 to 49 (median = 16). Sediments from reference marshes also had high enrichment factors (2-8) for lead, indicating that lead contamination is ubiquitous, possibly due to continuous input from atmospherically transported lead that was previously used as a gasoline additive. Copper, silver, and zinc in Stege Marsh were also enriched by anthropogenic input. Though nickel concentrations in Stege Marsh and reference marshes exceeded sediment quality guidelines, enrichment factors indicated nickel from anthropogenic input was negligible. Presence of nickel-rich source rock such as serpentinite in the San Francisco Bay watershed can explain high levels of nickel in this area. Coefficients of variation were significantly different between anthropogenically impacted and non-impacted metals and might be used as a less conservative indicator for anthropogenic input of metals when enrichment factors are not available.
|Number of pages||11|
|State||Published - Sep 2006|
Bibliographical noteFunding Information:
We would like to thank William Schilling and Marlene Relja for their help in laboratory chemical analyses. This research has been supported by a grant from the US Environmental Protection Agency’s Science to Achieve Results (STAR) Estuarine and Great Lakes (EaGLe) Coastal Initiative through funding to the Pacific Estuarine Ecosystem Indicator Research (PEEIR) Consortium, US EPA Agreement #EPA/R-82867601. Research activities at Tomales Bay were conducted under National Marine Sanctuary Permit #GFNMS-2002-005. The research was also supported in part by funding from the University of California Toxic Substances Research and Teaching Program.
- Anthropogenic input
- Enrichment factor
- Tidal salt marsh
- Trace metal
ASJC Scopus subject areas
- Environmental Engineering
- Chemistry (all)
- Environmental Chemistry
- Public Health, Environmental and Occupational Health
- Health, Toxicology and Mutagenesis