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Date Permissions Signed


Date of Award


Document Type

Masters Thesis

Degree Name

Master of Science (MS)



First Advisor

Donovan, Deborah Anne, 1964-

Second Advisor

Schulze, Sandra R.

Third Advisor

Shull, David, 1965-


Areas of oxygen depletion in the world's oceans have been on the rise, with the main culprits being anthropogenic causes such as eutrophication and pollution. Coastal marine areas, such as estuaries, are some of the more impacted ecosystems and they have been the focus of recent studies. This study focused on the effects of anoxia and the interactions it has with thermal tolerance in four local intertidal bivalves: Nuttallia obscurata, Venerupis phillipinarum, Leukoma staminea, and Mytilus trossulus. Nuttallia obscurata is a recent invader on which little physiological research has been conducted. Both V. phillipinarum and L. staminea are commercially important to local fisheries. Finally, M. trossulus is a native mussel commonly found in varying parts of the intertidal zone. The bivalves had anoxic conditions induced by using rubber bands to keep them shut. After a period of four days, they were tested for thermal tolerance by placing gill strips from the organism into one of three temperature treatments that varied per species. The gill tissue was evaluated for time to death. Gill tissue was also collected before the thermal tolerance experiment to examine stress protein levels using a Western blot analysis. Increasing temperature caused a decrease in survival time of gill tissue of all four species. However, there were no significant differences in temperature tolerance between the anoxic and control individuals in the bivalves. Levels of constitutive hsp70 were only found in Mytilus trossulus, with no difference in hsp70 expression between the control samples and those that experienced a period of anoxia. Thus, there was no evidence of either synergistic or antagonistic effects between the two stressors, anoxia and temperature, in this study. Bivalves are known to have excellent tolerance of anoxia because of their ability to decrease metabolic demands and utilize anaerobic pathways to produce needed energy.





Western Washington University

OCLC Number


Subject – LCSH

Bivalves--Effect of temperature on; Bivalves--Effect of water quality on; Hypoxia (Water)




masters theses




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