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Date Permissions Signed


Date of Award


Document Type

Masters Thesis

Degree Name

Master of Science (MS)


Environmental Sciences

First Advisor

Bingham, Brian L., 1960-

Second Advisor

Van Alstyne, Kathryn Lyn, 1962-

Third Advisor

Arellano, Shawn M.


Green tides are vast accumulations of green macroalgae that, in the last decade, have become a common nuisance worldwide. Due to compounds the algae release, the blooms may negatively affect other organisms. Ulvaria obscura, a dominant contributor to green tides along the Pacific coast of the United States, produces, among other compounds, dopamine, a catecholamine and neurotransmitter known to affect settlement and metamorphosis of marine invertebrates. We tested the effects of U. obscura exudates and commercially purchased dopamine on fertilization, early development, and larval survival and morphology of the sand dollar Dendraster excentricus and Pacific oyster Crassostrea gigas. The exudate and dopamine treatments did not strongly affect fertilization success of D. excentricus or C. gigas, but they did affect early development and larval morphology of D. excentricus and C. gigas. We found significant differences in archenteron length of D. excentricus gastrulae and shell morphology of C. gigas veligers exposed to the exudates or dopamine. Morphology of D. excentricus plutei also varied significantly among the exudate treatments with larval arm lengths being affected. Our data indicate that compounds released by U. obscura can impact development and, presumably, survival of embryos and larvae, but that the effects differ between species. The impacts could affect development rates, larval dispersal, recruitment and population dynamics of invertebrate species.





Western Washington University

OCLC Number


Subject – LCSH

Dendraster excentricus--Larvae--Development--Effect of drugs on; Dendraster excentricus--Reproduction--Effect of drugs on; Pacific oyster--Larvae--Development--Effect of drugs on; Pacific oyster--Reproduction--Effect of drugs on; Green algae--Chemical defenses; Dopamine




masters theses




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