Dissertation
PATTERNS AND PROCESSES OF ZOOPLANKTON INVASIONS IN THE PACIFIC NORTHWEST UNITED STATES
Doctor of Philosophy (PhD), Washington State University
01/2019
Handle:
https://hdl.handle.net/2376/117275
Abstract
Zooplankton communities are comprised of a wide range of microscopic organisms that occupy a central role in most aquatic ecosystems, but these communities face a range of strong environmental disturbances that encompass climate change, eutrophication, and the global spread of non-indigenous species. The research that I present here examines the impacts and underlying processes of zooplankton invasions across multiple perspectives (e.g. time-series analysis, ecological modeling, genetic analysis, biogeography) and a range of spatial and temporal scales. The first component of this dissertation is a genomic reconstruction of the invasion history of the copepod Pseudodiaptomus inopinus across the U.S. West Coast. This work shows that all invasive populations of P. inopinus in North America likely arose from a single native population in Asia, and that secondary spread across North American estuaries was likely the result of infrequent migration events. In the next component of this dissertation, my co-authors and I present a multivariate auto-regressive (MAR) model of plankton food web dynamics based upon a12-year record of monthly zooplankton samples from the upper Columbia River estuary. Our model results show negative effects of P. forbesi across multiple trophic levels, and that different life stages of P. forbesi were associated with different ecological impacts, with nauplii negatively impacting ciliates and autotrophs, and copepodite stages negatively impacting Daphnia and cyclopoid copepods. The next component of this dissertation is an analysis of zooplankton community data collected from 38 estuaries and rivers distributed across the U.S. West Coast. This work shows that the geographic distribution of at least six species of non-indigenous copepods and cladocerans is considerably greater than previously documented, and that some of these species appear to be rapidly spreading across the region. The final component of this dissertation is comprised of a global review of the literature on zooplankton invasions published in the last 20 years. This review shows that most studies of invasive zooplankton focus upon only a small number of taxa and waterbodies, and that the waters of less economically developed nations (most notably at tropical latitudes) are severely understudied.
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Details
- Title
- PATTERNS AND PROCESSES OF ZOOPLANKTON INVASIONS IN THE PACIFIC NORTHWEST UNITED STATES
- Creators
- Eric David Dexter
- Contributors
- Stephen M Bollens (Advisor)Gretchen Rollwagen-Bollens (Committee Member)Séverine Vuilleumier (Committee Member)Stephanie Hampton (Committee Member)Steve Katz (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- School of the Environment (CAHNRS)
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 172
- Identifiers
- 99900581618701842
- Language
- English
- Resource Type
- Dissertation