Interlocal Agreement with Washington State
Department of Natural Resources:
Smith Cove Blue Carbon
Monitoring Study- Phase 2
September 10, 2024
Kathleen Hurley, Sr. Environmental Program Manager
Maritime Environment & Sustainability
Agenda Item: 8g_supp
Meeting Date: September 10, 2024
Request
Request Commission authorization to execute a 5-year Interlocal
Agreement with the Washington State Department of Natural Resources
(DNR) to support the second phase of monitoring of the Smith Cove Blue
Carbon Project. Total estimated project cost is $227, 000.
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Smith Cove Project Goals
Carbon storage
– Generate carbon-rich biomass
– Increase retention time
Water quality
– Remove contaminants
– Lower temperature
– Offset ocean acidification (raise pH)
Fish & wildlife habitat
– Create feeding/shelter areas
– Increase overall productivity
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Phase 1: 2018-2023 Accomplishments
Between 2018-2021, bull kelp enhancement, eelgrass restoration, and outplant of
Olympia oysters were implemented at Smith Cove, followed by monitoring through
2023.
• Olympia oysters: Out-planted in two areas in 2018 and 2021 (delayed due to the COVID-19
pandemic). As of 2023, Olympia oyster populations are of moderate density.
• Algae: Rock reefs were established in January 2019, while the rock reefs were initially intended as
bull kelp substrate, they subsequently became populated by diverse macroalgal species, which
increased the carbon cycling capabilities of Smith Cove.
• Eelgrass: average percent coverage of plants within the 2,200 ft
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eelgrass study area increased from
29% to 57% between 2018-2022.
• Partnerships: Puget Sound Restoration Fund (kelp index station, kelp bulb counts); WA Dept. of
Natural Resources (on-going monitoring, octo-pot pilot study); Seattle Aquarium (kelp surveys)
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Rationale for Phase 2
• Continues progress on the Port of Seattle‘s Long Range Plan Objective 15, Priority
Action 4, “Optimize PORTfolio park and habitat restoration sites to
sequester greenhouse gases (GHG’s)”; and, Objective 17, “Restore, create,
and enhance 40 additional acres of habitat in the Green/Duwamish Watershed and
Elliott Bay.”
• Expands understanding of the benefits of these critical habitats in Central Puget
Sound related to carbon sequestration, water quality (specifically seawater
acidification) benefits, and habitat productivity.
• Long-term data collection will enable the Port to contribute knowledge and
expertise applicable to kelp and eelgrass restoration, water quality, and evaluate the
carbon sequestration potential in urban environments.
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Port Responsibilities:
• Provide $227,000 in funding to DNR.
• Port of Seattle will provide access to the Monitoring Project site and will
coordinate with designated DNR personnel for temporary use of Port
equipment for purposes of carrying out the Monitoring Project.
• Coordinate activities between DNR, Puget Sound Restoration Fund,
consultants, port, and interested community groups.
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Phase 2: 5-year Joint Project 2024-29
DNR Responsibilities:
o Staff time of a Natural Resource Scientist I, III, and IV for the duration
of this project.
o Collection and analysis of sediment samples to assess sediment carbon
sequestration.
o Monitor sediment accretion and surface sediment properties.
o Conduct vegetation surveys in the intertidal area within Smith Cove
o Include site in the State’s Acidification Nearshore Monitoring Network
(ANEMONE)
o Maintain/repair water quality sensors and other equipment at the site
o Generate a final report summarizing findings
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Project Schedule
Phase 2 includes evaluation of the characteristics of submerged aquatic
vegetation (macroalgae and eelgrass), carbon accretion, and carbon
sediment sources at the Smith Cove site.
– Project Planning and Permits (2024)
– Surface Sediment collection (2025-2028)
– Sediment accretion monitoring (2025-2028)
– Submerged aquatic vegetation monitoring (2025-2028)
– Reporting (2025-2028)
– Sediment core collection and analysist (2026)
– Final Report (2029)
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