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 Permissions Signed


Date of Award

Summer 2018

Document Type

Masters Thesis

Degree Name

Master of Science (MS)


Environmental Sciences

First Advisor

Matthews, Robin A., 1952-

Second Advisor

Bodensteiner, Leo R., 1957-

Third Advisor

Helfield, James M.


Macroinvertebrate abundances on six dominant macrophytes taxa were compared in Canyon Lake, Washington to determine whether there were patterns of association with macrophyte type or among assemblages of macroinvertebrates. Macrophytes and associated epiphytic macroinvertebrates were collected during August 2016. The dominant macrophyte distribution and lakes bathymetry were mapped in July 2016. The dominant macrophytes included Equisetum fluviatile, Fontinalis antipyretica, Potamogeton natans, Potamogeton epihydrus, Ranunculus aquatilis, and Vallisneria americana. Other non-dominant macrophytes included: Sparganium angustifolium, Sphagnum mosses, Nuphar polysepala, Characeae (stonewort), Isoetes (quillwort) and Potamogeton pusillus. Macroinvertebrate taxa were identified to the lowest practical taxonomic resolution; the dominant macrophytes were identified to species; other non-dominant macrophytes were identified to the lowest practical resolution.

Water quality samples were collected in June, July and August 2016 and were analyzed for temperature, dissolved oxygen, pH, conductivity, turbidity, alkalinity, chlorophyll, ammonium, nitrate+nitrite, total nitrogen, soluble reactive phosphorus, and total phosphorus. The summer water quality in Canyon Lake was characterized by warm water temperatures (11.4 - 20.2 ◦C) and high dissolved oxygen concentrations (8.6 - 9.9 mg/L) in the upper water column. The lake began to stratify in June, and by late August the dissolved oxygen was < 2 mg/L in the deepest part of the lake. The lake had soft, poorly buffered (< 60 mg-CaCO3 /L), and mildly acidic to near neutral water (pH = 6.6 - 7.2). The phosphorus and nitrogen concentrations were relatively low except in late summer near the bottom of the lake. The lake is stained brown from humic compounds and acids that leach from the extensive submerged and floating woody debris.

A total of 18,509 epiphytic macroinvertebrates were collected, in association with six different macrophyte taxa. Among these, 36 different macroinvertebrate taxa were identified. Basommatophora and Amphipoda constituted the most numerically abundant macroinvertebrate. Emergent and structurally simple macrophytes supported lower abundances of macroinvertebrates; more structurally complex macrophytes supported greater abundances of all macroinvertebrate groups. The simple, un-branched macrophyte Equisetum fluviatile consistently supported the lowest macroinvertebrate abundances; the highly branched and complex Ranunculus aquatilis supported the highest macroinverte brate abundances. Odonata and Trichoptera, which were rare compared to most taxa, were most commonly found among Fontinalis antipyretica, Ranunculus aquatilis, and Potamogeton epihydrus, which were complexly structure macrophytes. Hierarchical clustering on principal components generated two clusters of samples that corresponded best to low and high macroinvertebrate abundances. The remaining data factors that were explored did not correspond well to the identified cluster groups.




Epiphytic Macroinvertebrates, Macrophytes, Macrophyte Complexity, Principal Component Analysis, Hierarchical Clustering, Western Cascades



Western Washington University

OCLC Number


Subject – LCSH

Invertebrate communities--Washington (State)--Canyon Lake (Whatcom County); Epiphytes--Washington (State)--Canyon Lake (Whatcom County); Aquatic plants--Washington (State)--Canyon Lake (Whatcom County); Lake ecology--Washington (State)--Canyon Lake (Whatcom County); Hierarchical clustering (Cluster analysis)

Geographic Coverage

Canyon Lake (Whatcom County, 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 thesis for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.

Rights Statement

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 License.