Presentation Abstract

Fluctuations in Puget Sound water quality reflect a combination of natural variability and anthropogenic influence. Predictions of how future changes will unfold requires an understanding of the complex interplay between these factors. Recent and ongoing measurement of water quality parameters allow a thorough assessment of variability over short time scales, but understanding changes over longer (e.g., decadal) timescales is critical for forecasting future changes. Examining long term trends requires the use of historical data, however, measurements that pre-date modern monitoring programs can be scarce, and the detection limits are often higher than newer analytical techniques. Here, we will consider several possible methods to stitch together modern and historical data records of dissolved oxygen and nutrient concentrations while accounting for differences in sample rate, temporal coverage, and sensitivity of analytical techniques. To test different data analysis methods, data records with good temporal coverage that show discernible trends and/or high covariance with other environmental parameters will be used as the basis for simulating data with spotty temporal coverage (as might be expected for less commonly measured biogeochemical parameters like deep dissolved oxygen). Selected trend analyses will then be applied to these simulated time series records to assess method effectiveness in identifying a known feature. Top performing methods for trend analysis will then be applied to key biogeochemical parameters such as nitrate and deep dissolved oxygen. We report on the major covariates and trends identified and the associated statistical confidence intervals. These results will be part of a larger effort to determine how existing trends might play out under different anthropogenic input scenarios.

Session Title

Posters: Species & Food Webs

Keywords

Nutrient, Water Quality, Historical, Oxygen, Puget Sound, Marine

Conference Track

SSE18: Posters

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE18-114

Start Date

5-4-2018 11:30 AM

End Date

5-4-2018 1:30 PM

Type of Presentation

Poster

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Geographic Coverage

Salish Sea (B.C. and Wash.)

Rights

This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.

Type

text

Language

English

Format

application/pdf

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Apr 5th, 11:30 AM Apr 5th, 1:30 PM

Extending observations further: using historic biogeochemical data to understand trends in Puget Sound

Fluctuations in Puget Sound water quality reflect a combination of natural variability and anthropogenic influence. Predictions of how future changes will unfold requires an understanding of the complex interplay between these factors. Recent and ongoing measurement of water quality parameters allow a thorough assessment of variability over short time scales, but understanding changes over longer (e.g., decadal) timescales is critical for forecasting future changes. Examining long term trends requires the use of historical data, however, measurements that pre-date modern monitoring programs can be scarce, and the detection limits are often higher than newer analytical techniques. Here, we will consider several possible methods to stitch together modern and historical data records of dissolved oxygen and nutrient concentrations while accounting for differences in sample rate, temporal coverage, and sensitivity of analytical techniques. To test different data analysis methods, data records with good temporal coverage that show discernible trends and/or high covariance with other environmental parameters will be used as the basis for simulating data with spotty temporal coverage (as might be expected for less commonly measured biogeochemical parameters like deep dissolved oxygen). Selected trend analyses will then be applied to these simulated time series records to assess method effectiveness in identifying a known feature. Top performing methods for trend analysis will then be applied to key biogeochemical parameters such as nitrate and deep dissolved oxygen. We report on the major covariates and trends identified and the associated statistical confidence intervals. These results will be part of a larger effort to determine how existing trends might play out under different anthropogenic input scenarios.