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Date of Award
Masters Field Project
Department or Program Affiliation
Hollenhorst, Steven J.
This paper explores recovery of eelgrass (Zostera marina L.) meadows through seed-based restoration to address declines from natural and anthropogenic disturbances. The study focuses on the Joe Leary meadow site in Padilla Bay, Washington, aiming to (1) determine the spatial distribution of perennial and annual Z. marina, (2) understand variation in flowering shoot density and potential seed production, and (3) compare the phenology of flowering shoots. These objectives were investigated using field-based methods to collect presence/absence transect data for delineation, quadrat-based count data, and monitor seed development. Data collection occurred in the summer throughout the flowering life stage of eelgrass in the site. The study found spatial and temporal variation in the distribution, density, and phenology of flowering perennial and annual populations. Delineation methods revealed that annuals have a similar range in the intertidal as perennials, with differences highlighted in response to potential stress indicators such as proximity to the slough, algal mats, or elevation. Quadrat-based monitoring found annual shoots in the transect higher in the intertidal, above the perennial population. Phenology data indicated that perennial shoots flower about a month prior to annual shoots. While the study advises against using perennial flowering shoots for restoration due to low densities, it emphasizes Joe Leary's potential as a donor site for flowering annuals for seed-based restoration. Careful considerations are crucial to avoid unintended introductions of non-native species. The research concludes with recommendations for refining delineation methods, enhancing understanding of eelgrass population dynamics, and optimizing seed collection strategies for genetically diverse and resilient restoration in the face of climate change.
Eelgrass, Zostera marina, intertidal, San Juan Islands, Padilla Bay, Restoration, GIS, population dynamics, ecosystem management, sustainability, donor site, eelgrass meadow
Western Washington University
Subject – LCSH
Zostera marina--Washington (State)--Padilla Bay; Estuarine restoration--Washington (State)--Padilla Bay; Ecosystem management--Washington (State)--Padilla Bay
Padilla Bay (Wash.)
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Wilmerding, Yuki, "Investigating perennial & annual eelgrass (Zostera marina L.) in Padilla Bay as potential donor sources for seed-based restoration" (2023). WWU Graduate School Collection. 1260.