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BACKGROUND AND STATUS of RMP SEDIMENT STUDIES

BACKGROUND AND STATUS of RMP SEDIMENT STUDIES. RMP EEWG MEETING September 6, 2007. RMP SEDIMENT COMPONENTS. 1. Status and Trends Sediment Characteristics (grain-size, TOC, etc.) Sediment Toxicity ( Eohaustorius and elutriate – larval bivalves) Pilot and Special Studies

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BACKGROUND AND STATUS of RMP SEDIMENT STUDIES

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  1. BACKGROUND AND STATUS of RMP SEDIMENT STUDIES RMP EEWG MEETING September 6, 2007

  2. RMP SEDIMENT COMPONENTS • 1. Status and Trends • Sediment Characteristics (grain-size, TOC, etc.) • Sediment Toxicity (Eohaustorius and elutriate – • larval bivalves) • Pilot and Special Studies • Collaborative Studies

  3. RMP PILOT AND SPECIAL STUDIES • Benthic Pilot Study (Thompson et al., 2000) • Development of Toxicity Tests (Weston, 1995) • Wetlands Pilot Study (Collins et al. 1995) • Sediment Work Group / Atlas (Thompson et al. 1999) • Episodic Toxicity / TIE studies (Anderson et al. 2007) • Influence of chem. & phys. factors (Melwani, Thompson, 2007) • on benthos

  4. COLLABORATIVE STUDIED • Local Effects Monitoring Program (BACWA, 1994-1996) • CisNet (1999-2001, EPA / UCD) • EMAP SF Estuary Surveys (EPA, NOAA) • State Board BioCriteria (SWRCB, SCCWRP) • SQO 2005-present (SWRCB, SCCWRP) • - Several publications • - Delta Sediment Survey (DWR) • Non-Indigenous Benthos (EPA, 2000) • Long Term Sediment Management Study (ACOE, BCDC) • Delta Dredged-Sediment Reuse Study (CALFED, RB 5)

  5. CONCEPTUAL MODELS • Mechanisms of Exposure and Effects • - Sediment Atlas, 1999 • Toxicity Dose – Response • - Anderson et al., 2007 • Benthic Response to “Disturbance” • - Thompson et al., 2004

  6. WHAT HAVE WE LEARNED? SEDIMENT CONTAMINATION • Sediments may contain elevated levels of several • contaminants. • - As, Cu, Zn, Ni • - DDT, PAHs, Chlordanes • - Mixtures • Highest concentrations in muddy sediments near • margins, mouths of tributaries, Ports, BPTCP ‘hot- • spots’.

  7. WHAT HAVE WE LEARNED? SEDIMENT TOXICITY • Sediment toxicity is widespread and persistent in • San Francisco Estuary • Different results for different tests • More toxicity in wet season, and at margins • Toxicity has been associated with: • - Chlordanes • - Mixtures • - Cu ions in pore water, Suisun Bay • - Non-polar organics, Redwood Ck. • - Pyrethroids in some tributaries, Delta

  8. WHAT HAVE WE LEARNED? BENTHOS • Assemblage distribution and composition • - have we sampled all of them? • Assemblages distribution changes in response to • fresh water inflows • Species composition and abundances within assemblages • may change in response to contamination, sediment • type, salinity,different in different parts of the Estuary. • Causes mostly unknown. Associated with specific • mixtures, interaction of factors

  9. MANAGEMENT CONTEXT • TMDLs in place that include sediments as sources • SQO will be Implemented in next few years. • RMP role: continue to provide information to RB and • participants. • Stressor ID: Must know cause and effect to effectively • implement TMDLs, source controls.

  10. INFORMATION NEEDS AND NEXT STEPS • Stressor Identification for SQOs • Identify contaminants that cause toxicity, benthic impacts • SQO Phase II, Delta sampling • Include benthic sampling in S & T • Revised Long-Term Sediment Studies Plan for RMP

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