Presentation Abstract

How much has the total organic carbon deposited into the water column and sediments of Puget Sound increased due to human activity? How has that increase impacted sediment flux rates, hypoxia and the carbonate system balance? These are two important questions with answers that are still elusive. To date, both marine and freshwater organic carbon measurements in Puget Sound are relatively sparse. In the long-term, inadequate temporal and spatial organic carbon data may lead to an incomplete and incoherent understanding of carbon cycling in the Puget Sound. The Salish Sea Model, developed by PNNL in collaboration with Department of Ecology, provides insights into the extent of organic carbon loading and concentrations in the Puget Sound. Model scenario runs indicate that autochtonous organic detritus derived from increased productivity related to human nitrogen loading, combined with allochthonous carbon from direct loading due to human activity, has resulted in an increased loading of non-algal organic carbon ranging from 20 and 25% in a significant portion of the Puget Sound’s main basin, as well as in multiple inlets. This increase in organic carbon is expected to have an impact in heterotrophic respiration rates and eutrophication. This presentation will focus on loading rates and predicted organic carbon concentrations throughout the Puget Sound using the Salish Sea Model. It will point to the need for enhanced dissolved and particulate organic carbon measurements in our region, as well as basin-scale measurements of respiration rates, to optimize the alignment of on-going, long term monitoring and modeling efforts.

Session Title

Transcending the Land-Ocean Boundary. Responses of Ecosystem Process to Climate and Human Impacts Across a Wide Spectrum of Processes, Habitats and Space

Keywords

Organic carbon, DOC, TOC, POC

Conference Track

SSE16: Long-Term Monitoring of Salish Sea Ecosystems

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE16-568

Start Date

5-4-2018 2:30 PM

End Date

5-4-2018 2:45 PM

Type of Presentation

Oral

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, 2:30 PM Apr 5th, 2:45 PM

Predicting Puget Sound's organic carbon—and why we need enhanced monitoring

How much has the total organic carbon deposited into the water column and sediments of Puget Sound increased due to human activity? How has that increase impacted sediment flux rates, hypoxia and the carbonate system balance? These are two important questions with answers that are still elusive. To date, both marine and freshwater organic carbon measurements in Puget Sound are relatively sparse. In the long-term, inadequate temporal and spatial organic carbon data may lead to an incomplete and incoherent understanding of carbon cycling in the Puget Sound. The Salish Sea Model, developed by PNNL in collaboration with Department of Ecology, provides insights into the extent of organic carbon loading and concentrations in the Puget Sound. Model scenario runs indicate that autochtonous organic detritus derived from increased productivity related to human nitrogen loading, combined with allochthonous carbon from direct loading due to human activity, has resulted in an increased loading of non-algal organic carbon ranging from 20 and 25% in a significant portion of the Puget Sound’s main basin, as well as in multiple inlets. This increase in organic carbon is expected to have an impact in heterotrophic respiration rates and eutrophication. This presentation will focus on loading rates and predicted organic carbon concentrations throughout the Puget Sound using the Salish Sea Model. It will point to the need for enhanced dissolved and particulate organic carbon measurements in our region, as well as basin-scale measurements of respiration rates, to optimize the alignment of on-going, long term monitoring and modeling efforts.