Presentation is loading. Please wait.

Presentation is loading. Please wait.

Draft Data - Do not cite or quote Sediment contamination Sediment toxicity Benthic community structure Results used to identify and map areas of unimpacted.

Similar presentations


Presentation on theme: "Draft Data - Do not cite or quote Sediment contamination Sediment toxicity Benthic community structure Results used to identify and map areas of unimpacted."— Presentation transcript:

1 Draft Data - Do not cite or quote Sediment contamination Sediment toxicity Benthic community structure Results used to identify and map areas of unimpacted to clearly impacted sediments Current RMP toxicity tests are those recommended for the accepted statewide SQO methods for bays and estuaries, EXCEPT… Sediment Quality Assessment Toxicity test data used in a weight-of-evidence:

2 Draft Data - Do not cite or quote Excerpt from SQO Staff Report - Table 5.2 List of candidate sediment toxicity tests The SQO recommends the use of sediment water interface (SWI) samples

3 Draft Data - Do not cite or quote Mussel embryo development 48-h exposure Sublethal endpoint Sediment elutriate VS. Sediment-water interface exposure

4 Draft Data - Do not cite or quote The TRC needs to decide if the RMP should adopt, add, or study the sediment-water interface (SWI) bivalve test in 2008.

5 Draft Data - Do not cite or quote What are the issues? Comparison to historic RMP/other programs Interpretation (Ecological Relevance) Cost

6 Draft Data - Do not cite or quote Comparison to historic RMP data Bivalve Methods Study 48-hr. sublethal development test Elutriate (1:4 dil. VS. SWI intact cores) 14 stations (52 samples).

7 Draft Data - Do not cite or quote Rivers Grizzly Bay Napa River Davis Point Coyote Creek San Bruno Shoal Horseshoe Bay Redwood Creek South Bay RMP Elutriate & SWI bivalve development tests (N=52) Yerba Buena Is Red Rock Alameda San Jose (LEMP)

8 Draft Data - Do not cite or quote Rivers Grizzly Bay Napa River Davis Point Redwood Creek Yerba Buena Island Horseshoe Bay Coyote Creek San Jose Legend: Amphipod and Bivalve Sediment Toxicity Results (BF21) Pulse of the Estuary, 2003 South Bay (BA21)

9 Draft Data - Do not cite or quote Interpretation SWI tests are thought to be more ecologically relevant However, not much in known about contaminant flux and exposure SCCWRP study (4 samples) to determine if homogenized sediments can be left to equilibrate and used in the SWI test.

10 Draft Data - Do not cite or quote Recommendation RMP S&T should switch to the intact SWI method to be comparable to recommended SQO methods that have been endorsed by a panel of national experts –However, this will result in a NEW toxicity measure and will not be comparable with historic RMP data (largely an issue in Suisun Bay & Lower South Bay Regions) Consider adding elutriate tests in Suisun Bay and Lower South Bay Regions and evaluate chemistry in the test water of both tests to begin to understand differences in contaminant exposures.

11 Draft Data - Do not cite or quote Cost $20 more per sample

12 Draft Data - Do not cite or quote Cost

13 Draft Data - Do not cite or quote Rivers Grizzly Bay Napa River Davis Point Coyote Creek San Bruno Shoal Horseshoe Bay Redwood Creek South Bay RMP Elutriate & SWI bivalve development tests (N=52) Yerba Buena Is Red Rock Alameda San Jose (LEMP)

14 Draft Data - Do not cite or quote Further Study Evaluate the comparability of intact SWI cores vs homogenized sediment on a variety of sediments in order to make a confident assessment that the two sampling methods can be used and are equally ecologically relevant. –SCCWRP is beginning to investigate (4 samples) –RMP?


Download ppt "Draft Data - Do not cite or quote Sediment contamination Sediment toxicity Benthic community structure Results used to identify and map areas of unimpacted."

Similar presentations


Ads by Google