Presentation Abstract

The potential for seagrass (Zostera marina) habitats to store carbon is a topic of interest to resource managers and ecosystem scientists as they strive to develop and evaluate climate change mitigation strategies. I investigated the sources of carbon and nitrogen stored in Zostera marina habitats within the Salish Sea. I compared two sites, the Skagit River delta (delta) and Padilla Bay (embayment), in order to compare carbon storage and the sources of stored carbon between these two shoreline types. Within each site, I collected sediment cores in Z. marina meadows and on unvegetated mudflat. I measured changes in carbon density and isotopic signatures of carbon and nitrogen with depth. Isotopic signatures showed significant differences in carbon and nitrogen between the delta and embayment sites and also between Z. marina meadows and unvegetated mudflat. In the Skagit delta, cores taken from Z. marina habitat were depleted in ∂13C compared with cores taken from unvegetated habitat. Conversely, in the Padilla Bay embayment, cores taken from Z. marina habitat were enriched in ∂13C compared with cores taken from unvegetated habitat, suggesting that carbon and nitrogen sources varied between each site and within Z. marina habitats. In the next step of this research, a Bayesian mixing model will be used to estimate the contribution of likely carbon sources within the Skagit delta and Padilla Bay embayment. This analysis may clarify the differences between source(s) of carbon and nitrogen supplied to each site, and whether sources have changed over time. In addition, this model may uncover the different source(s) of carbon and nitrogen stored within Z. marina meadows and unvegetated mudflat. This research may help shed light on the carbon and nitrogen storage dynamics within these sites and the mechanisms that drive carbon storage within the Skagit Delta and Padilla Bay.

Session Title

Seagrass Cross-border Connections: Status and Trends

Keywords

Blue carbon, Seagrass

Conference Track

SSE4: Ecosystem Management, Policy, and Protection

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE4-331

Start Date

5-4-2018 10:30 AM

End Date

5-4-2018 10:45 AM

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, 10:30 AM Apr 5th, 10:45 AM

Examining sources of sediment carbon stored in seagrass habitats across the Skagit Delta and Padilla Bay

The potential for seagrass (Zostera marina) habitats to store carbon is a topic of interest to resource managers and ecosystem scientists as they strive to develop and evaluate climate change mitigation strategies. I investigated the sources of carbon and nitrogen stored in Zostera marina habitats within the Salish Sea. I compared two sites, the Skagit River delta (delta) and Padilla Bay (embayment), in order to compare carbon storage and the sources of stored carbon between these two shoreline types. Within each site, I collected sediment cores in Z. marina meadows and on unvegetated mudflat. I measured changes in carbon density and isotopic signatures of carbon and nitrogen with depth. Isotopic signatures showed significant differences in carbon and nitrogen between the delta and embayment sites and also between Z. marina meadows and unvegetated mudflat. In the Skagit delta, cores taken from Z. marina habitat were depleted in ∂13C compared with cores taken from unvegetated habitat. Conversely, in the Padilla Bay embayment, cores taken from Z. marina habitat were enriched in ∂13C compared with cores taken from unvegetated habitat, suggesting that carbon and nitrogen sources varied between each site and within Z. marina habitats. In the next step of this research, a Bayesian mixing model will be used to estimate the contribution of likely carbon sources within the Skagit delta and Padilla Bay embayment. This analysis may clarify the differences between source(s) of carbon and nitrogen supplied to each site, and whether sources have changed over time. In addition, this model may uncover the different source(s) of carbon and nitrogen stored within Z. marina meadows and unvegetated mudflat. This research may help shed light on the carbon and nitrogen storage dynamics within these sites and the mechanisms that drive carbon storage within the Skagit Delta and Padilla Bay.