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Ecology-PSAMP Current Spatial/Temporal Monitoring 2002-Present

Ecology staff screening infaunal samples in Sinclair Inlet.

Environmental Management Application

The current PSAMP Sediment Component Spatial Monitoring element provides environmental managers with a recent characterization of sediment condition (i.e., the spatial extent of sediment quality degradation) in eight Puget Sound regions sampled on an annual, rotational cycle.

Temporal changes can also be assessed by comparison of new regional data with baseline data to determine whether sediment quality in each Puget Sound region is improving, degrading, or remaining the same over time.

Background

Sediment Monitoring Program Revised

After completion of the 1997-1999 PSAMP/NOAA partnership work, Ecology's Marine Sediment Monitoring Team revised the spatial sediment monitoring program to include a more refined probabilistic sampling design (below) and to incorporate a temporal element for quantification of large-scale regional changes in sediment quality over time.

A refined list of sampling parameters was generated, and the original study area was expanded to include the bays and inlets of the San Juan Archipelago, Admiralty Inlet, and the eastern Strait of Juan de Fuca. A nested set of sampling frames, including the whole Sound, eight Puget Sound sediment monitoring regions, and five strata were defined. Each region will be sampled, beginning in 2006, on an annual rotational cycle, alternating 9 years of regional sampling with 1 year of focused embayment sampling or specialized projects. (Sampling schedule.)

Results will include spatial characterization and quantification of sediment quality for a different region each year, along with temporal comparison of this recently collected data to the older baseline data. Sediment quality characteristics measured will include the Sediment Quality Triad of toxicity, chemistry, and infaunal community structure.

Sediment Quality Baseline Conditions Established for Puget Sound

In 2002 and 2003, prior to commencement of this 10-year rotational sampling cycle, sediments from the newly added study areas (San Juan Archipelago, Admiralty Inlet, and eastern Strait of Juan de Fuca) were sampled and analyzed for the Sediment Quality Triad of parameters. The 1997-2003 sediment data were then used to quantify sediment quality baseline conditions for each of the 8 sediment monitoring regions and for the whole Puget Sound study area.

Goals and Objectives

The overall goals of the sediment monitoring component of the PSAMP are to:

1. Assess the health of Puget Sound sediments and document geographic patterns in the conditions of the sediments.
2. Document natural and human-caused changes over time in Puget Sound sediments.
3. Identify existing sediment problems and, where possible, provide data to help target sources.
4. Provide sediment data to assist the Puget Sound Partnership and others in measuring the success of environmental programs.
5. Support sediment-related research activities by making available scientifically valid sediment quality data.

Specific objectives of the spatial surveys are to:

1. Determine the incidence and severity of toxicity and chemical contamination of sediments.
2. Identify spatial patterns and changes in sediment toxicity and chemical concentrations as defined with the selected methods.
3. Estimate the spatial extent of toxicity and chemical contamination, as defined with the selected methods, in surface sediments as percentages of the total survey area.
4. Describe the composition, abundance, and diversity of sediment-dwelling organisms at each sampling location.
5. Determine the degree of agreement among the sediment chemistry, toxicity, and sediment-dwelling invertebrate communities in classification of sediment quality.
6. Determine the spatial patterns and extent of degraded conditions based upon a weight of evidence formed with the three sediment quality measures.
7. Compare the current extent of degraded conditions with baseline conditions to determine the change in sediment quality over time.

Sampling Design

Regional and Embayment Rotational Sampling

With guidance from the PSAMP Steering Committee, the Puget Sound sediment study area has been divided into eight sediment monitoring regions defined by oceanographic and geological features of Puget Sound, as well as the distribution of biota (fish, birds, and marine mammals) throughout the Sound. In addition, five sediment monitoring strata, defined by major geographic features and degree of anthropogenic (human-caused) activity (strata definitions), have also been delineated within each region. Thirty to forty sediment samples will be collected annually, alternating 9 years of regional sampling with one year of focus embayment sampling or specialized projects.

Data will be summarized annually to spatially characterize the sediments in each monitoring region, the strata within each region, and ultimately, Puget Sound as a whole. Newly collected regional data will be compared with historical data to determine changes between sampling periods.

Probabilistic Survey Design

With assistance from EPA’s Aquatic Resources Monitoring Design and Analysis Team in Corvallis, Oregon, the probabilistic random, stratified sampling design was refined using a spatially-balanced, generalized random tessellation stratified (GRTS) multi-density survey design, as described by Stevens (1997), and Stevens and Olsen (1999, 2002). The GRTS design incorporates a hierarchical randomization process to ensure the sample is spatially-balanced across the PSAMP study region. It also allows sites to be selected with unequal probability to satisfy the sample size requirements by basin and category.

Quality Assurance Project Plan (QAPP)

Dutch, M., Edward Long, Sandra Aasen, Kathy Welch, and Valerie Partridge. In preparation. Puget Sound Ambient Monitoring Program: Marine Sediment Monitoring Component - Revised Quality Assurance Project and Implementation Plan. Spatial/Temporal Component. Washington State Department of Ecology, Olympia, WA.

Findings

Puget Sound baseline data collected from 1997-1999 and 2002-2003 by the PSAMP/NOAA Partnership were used to calculate the spatial extent of degraded sediment quality in Puget Sound using the Sediment Quality Triad Index. Findings of this survey concluded that:

• The majority (65%) of Puget Sound has high-quality surficial sediments.
• There is a sizeable area of Puget Sound (35%) classified with intermediate-quality sediments, found primarily in the Whidbey basin and Central Sound regions.
• The health of Puget Sound may be negatively affected by a small area (<1%) of degraded sediments found in the major urban embayments (i.e., Everett Harbor, Elliott Bay, Commencement Bay).

These values have established a baseline for Puget Sound and will be compared with similar values generated by the PSAMP Sediment Component in the future to determine changes in sediment condition over time throughout Puget Sound.

Publications

Data

Raw data can be obtained by downloading the compressed Microsoft Access database (PSAMP Sediment Monitoring database),or by contacting Sandra Aasen sgei461@ecy.wa.gov.

Literature Cited

Stevens, D.L., Jr. (1997) Variable density grid-based sampling designs for continuous spatial populations. Environmetrics, 8, 167-95.

Stevens, D.L., Jr. and Olsen, A.R. (1999) Spatially restricted surveys over time for aquatic resources. Journal of Agricultural, Biological, and Environmental Statistics, 4, 415-28.

Stevens, D.L., Jr. and Olsen, A.R. (2003) Variance estimation for spatially balanced samples of environmental resources. Environmetrics 14:593-610.