The vast majority of theses in this collection are open access and freely available. There are a small number of theses that have access restricted to the WWU campus. For off-campus access to a thesis labeled "Campus Only Access," please log in here with your WWU universal ID, or talk to your librarian about requesting the restricted thesis through interlibrary loan.

Date of Award

Fall 2023

Document Type

Masters Field Project

Department or Program Affiliation

Padilla Bay


Environmental Studies

First Advisor

Hollenhorst, Steven J.

Second Advisor

Yang, Sylvia


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

OCLC Number


Subject – LCSH

Zostera marina--Washington (State)--Padilla Bay; Estuarine restoration--Washington (State)--Padilla Bay; Ecosystem management--Washington (State)--Padilla Bay

Geographic Coverage

Padilla Bay (Wash.)




masters theses




Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author’s written permission.