Sediment Toxicity Monitoring S&T program 1993-2005

Toxicity is persistent in the Estuary and more frequent in the northern and southern regions.

Between 1997-2001

67% of S&T sediment samples were toxic to either species:

Eohaustorius (amphipod)

Mytilus (bivalve larvae)

0%

25%

50%

75%

1993-1999 1993-1999 2000-2005

Time Period

% o

f A

mp

hip

od

Su

rviv

al T

es

ts

tha

t w

ere

To

xic Winter

SummerSummer

Change in the S&T Experimental Design in 2000

Less toxicity seen in the summer

New Proposal

The TRC asked us to develop a new proposal that focused on getting at what might be causing the persistent sediment toxicity observed in the Status and Trends Program

Get review and comments from the Toxicity Workgroup

The Toxicity Workgroup met (Nov. 27th)

Endorsed the overall proposal:• Liked the standard 10-day estuarine amphipod test• Focus on Bay-margins in the winter• New sediment TIE methodology is well developed

Study is consistent with what the workgroup had proposed in past

• Want to participate in developing the site selection criteria

and the prioritized list of sites to investigate

Sediment TIE Study Proposal

TIEs will be conducted with the estuarine amphipod Eohaustorius estuarius.

The goal of this study is to use newly-developed sediment TIE methods to determine the possible causes of sediment toxicity at the margins of the Estuary.

Sediment TIE Study Proposal

1. Develop a list of sampling sites

2. Screen sites to locate two toxic sites

3. Conduct the TIE study at these sites

Sediment TIE Study Proposal

- Three phase sediment TIE

I. Characterization

II. Identification

III. Confirmation

- Bulk sediment and pore-water samples

- Standard EPA toxicity methods for estuarine sediments

(E. estuarius 10-day survival)

Sediment TIE Study Proposal

1. Develop a list of sampling sites

Sediment TIE Study Proposal

2. Screen sites to locate two toxic locations

Sample first four sites

if toxic conduct TIEs, Chemistry & assess duration

If not toxic sample four more sites

if toxic conduct TIEs, and Chemistry

Sediment TIE Study Proposal

2. Screen sites to locate two toxic locations

Sample first four sites

if toxic conduct TIEs, Chemistry & assess duration

If not toxic sample four more sites

if toxic conduct TIEs, and ChemistryIf none of the eight sites are toxic enough to warrant a full TIE, sample last four sites (after)

if toxic conduct TIEs, and Chemistry

Summary- Develop a prioritized list of sites (12)

- Sample first four -4if toxic conduct TIEs, Chemistry and assess duration

- If not toxic sample four more sites -4if toxic conduct TIEs, and Chemistry

If none of eight sites are toxic consult TRC for approval of four more sites in 2008

- Sample last four sites -4if toxic conduct TIEs, and Chemistry 0

Budget2007 Episodic Toxicity Budget: $140,000

Sediment TIE Study Proposal 2007: $96,600

No. Smpls Cost $ No. Smpls Cost $Project Mngt & Sampling 8 20,800 4 4,000Sediment Chemistry 2 16,605 <-- <--Sediment Quality 10 1,900 4 1,936Screening Toxicity Tests 8 6,820 4 3,810TIE Study 2 40,700 <-- <--Total Cost Estimate 86,825 9,746 <-- indicates that 2007 funds will be used

2007 Study 2008 Addition