1.0 Introduction

Contents

Tables

Figures

Download PDF version

1.1 Monitoring Design

The RMP sampling design was based on the Bay Protection and Toxic Cleanup Program (BPTCP) Pilot Studies developed by the Regional Board (Flegal et al., 1994). The reasoning behind the original design, with stations located along the "spine" of the Estuary, was to include stations that, in a long-term monitoring program, would indicate spatial and temporal trends in toxicity and chemistry, determine background concentrations for different segments of the Estuary, and assess whether there were high levels of contaminants or toxicity. Several new stations were added in 1994 to fill spatial gaps and to begin monitoring near major tributaries (SFEI, 1995). Additionally, two stations were added in 1994 in the southern-most end of the Estuary in cooperation with the Cities of San Jose (station C-3-0) and Sunnyvale (station C-1-3) and the Regional Board as part of their National Pollutant Discharge Elimination System (NPDES) monitoring.

The RMP station design has provided a picture of the range of conditions found in deeper parts of the Estuary, influenced by riverine, seasonal, and daily natural processes. During the re-design process, options for incorporating more near-shore stations, evaluating overall Estuary condition at statistically representative sites, or conducting intensive embayment studies will be explored.

Five types of samples were collected in the 1998 Status and Trends Program:

1. Conventional water quality and chemistry.
2. Aquatic bioassays.
3. Sediment quality and chemistry.
4. Sediment bioassays.
5. Transplanted, bagged bivalve bioaccumulation, survival, and condition.

Complete listings of all parameters measured in 1998 are included in Table 1.2. For a detailed description of methods of collection and analysis see Description of Methods. RMP data included in this report can be obtained by contacting SFEI or by accessing SFEI’s on-line database at: http://www.sfei.org/rmp/data.htm.

Locations of the twenty-two RMP, two Southern Slough (C-3-0, C-1-3), and Estuary Interface sampling stations are shown in Figure 1.1; Table 1.3 lists the station names, codes, locations, and sampling dates for all 1998 stations. Water, sediment, or bioaccumulation sampling sites with the same station name may have different station codes as they are situated at slightly different locations (latitude, longitude) due to practical considerations such as sediment type or ability to deploy bivalves. For example, at the South Bay site, BA20 is the water station code and BA21 is the sediment station code.

Sampling occurred during three periods in 1998: during the wet season (January-February), a period of declining Delta outflow (April), and during the dry season (July-September). The rationale for taking seasonal "snapshots" is to relate contaminant data during hydrologically different periods of the year with higher-frequency measurements conducted by the U.S. Geological Survey (USGS)and to evaluate the influence of natural variability on the contaminant signal. As part of the RMP re-design, the use of more intensive data on tides, Delta outflow, salinity gradients, algal blooms, and other parameters will be evaluated in greater detail to minimize the natural noise around any signals of water quality improvement or degradation over time.

Not all parameters were measured at all RMP stations each sampling period. Sampling activities at each station are listed on Table 1.3.

Water and sediment samples were collected from the R/V David Johnston chartered through the University of California, Santa Cruz. Each sampling cruise starts with water sampling at all RMP stations. Sediment sampling is then conducted with a separate run though the Estuary. Each complete sampling run requires three to five days. Bivalve monitoring consisted of three parts: deployment of transplants from reference sites, maintenance, and retrieval. Most of this work was conducted aboard the R/V Questuary, owned by San Francisco State University. The California Department of Water Resources provided back-up services for bivalve cruises.

The U.S. Geological Survey took monthly measurements of five water quality parameters to supplement RMP monitoring. This additional monitoring was designed to describe the changing spatial patterns of water-quality variability from the lower Sacramento River to the southern limit of the South Bay.

Field sampling and laboratory analysis were coordinated by the RMP prime contractor, Applied Marine Sciences in Livermore, California. In addition, a group of Principal Investigators also participated in the RMP (Table 1.4).

back to top

1.2 References

Flegal, A.R., R.W. Risebrough, B. Anderson, J. Hunt, S. Anderson, J. Oliver, M. Stephenson, and R. Packard. 1994. San Francisco Estuary Pilot Regional Monitoring Program: Sediment Studies. San Francisco Bay Regional Water Quality Control Board, State Water Resources Control Board.

SFEI. 1995. 1994 Annual Report: San Francisco Estuary Regional Monitoring Program for Trace Substances. Prepared by the San Francisco Estuary Institute, Oakland, CA. 339p.

back to top