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Date Permissions Signed

11-11-2011

Date of Award

2011

Document Type

Masters Thesis

Degree Name

Master of Science (MS)

Department

Biology

First Advisor

Sulkin, Stephen D.

Second Advisor

Van Alstyne, Kathryn Lyn, 1962-

Third Advisor

Donovan, Deborah Anne, 1964-

Abstract

Current global conditions are leading to increased numbers of harmful macroalgal blooms, which have detrimental effects on the ecosystems in which they occur. Macroalgae produce harmful chemicals such as ROS (reactive oxygen species) and dopamine. These chemicals may be produced in high quantities in response to environmental stresses, such as increasing water temperature, emersion, hypoxia, and then subsequently introduced into the aquatic environment. In Washington State, little work has been done to quantify ROS accumulation by macroalgae, or investigate oxidant impacts on invertebrates. This project investigated the impacts of environmental (emersion, water temperature, hypoxia) and chemical (dopamine) stressors on oxidant accumulation in two bloom forming macroalgae (Ulvaria obscura and Ulva lactuca) in Washington State. The effects of hydrogen peroxide (H2O2) on Metacarcinus magister zoeae survival and development were also investigated. Oxidant concentrations changed in U. obscura after exposure to emersion stress. Seawater with previously emersed algae accumulated oxidants at a rate that was one order of magnitude less than seawater with algae that remained submerged. Water temperature and environmental dopamine significantly changed oxidant concentrations in U. lactuca, but not U. obscura. Seawater with U. lactuca that were exposed to 10o C seawater accumulated more oxidants than algae exposed to 15o C and 20o C seawater. Stage I Metacarcinus magister zoeae were exposed to hydrogen peroxide levels ranging from no hydrogen peroxide to 6 μM. All zoeae had similar mortality rates; those exposed to hydrogen peroxide had slightly, but not significantly higher mortalities. Zoeae in all treatments also had similar stage durations of 11.6 days. These results suggest that zoeal survival and development rate are unaffected by accumulated oxidants in the concentrations and exposure times used in this experiment.

Type

Text

Publisher

Western Washington University

OCLC Number

761333159

Digital Format

application/pdf

Geographic Coverage

Washington (State)

Genre/Form

Academic theses

Language

English

Rights

Copying of this thesis 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.

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Biology Commons

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